I would like to talk a little bit about my experience with the Spanish with Listening test, since there are barely any posts about it. I hope this is useful to anyone who is thinking about taking it! 
A little bit of background: I’ve been taking Spanish since middle school and am currently in AP Spanish Lang. Never really considered myself exceptionally fluent in the language or anything and have had no study abroad or much outside-of-school experience, though I’ve constantly received high marks (A/A+'s) in my Spanish classes. I took the test about a month ago, got a >700 and started prepping since around July or August (~3-4 months), taking one practice test per week and watching one or two episode of shows in Spanish on a daily basis.
Study material: Blue Book, Barron’s, Princeton (practice tests), and Shmoop (just the listening exercises, but I didn’t find it useful at all to be honest)
In terms of the reading portion, I think one of the biggest thing is having a strong grasp of ALL the grammar rules. Seriously, every single one of them (present, preterite, imperfect, present/past subjunctive, present/preterite perfect, pluperfect, and some more that I don’t remember on the top of my head, but you get the idea). You should definitely be aware of some random circumstances certain tenses can be used in as well (such as using the future tense to express wonder in the present, using the subjunctive for action not yet completed, etc etc). Direct/Indirect Object and prepositional stuff like lo/el/la que/cual seems to pop up often as well. It’s not that every single of them will be covered in one test, but you never know which one may come up, so you have to be ready for any of them. This all is mostly memorization and practice. I personally found Barron’s grammar review and exercises very, very useful. It basically covers everything you need to know, and there are tons of grammar exercises you can easily find online to complement the topics as well. A site that I remember browsing for some fundamentals I forgot is StudySpanish.com. I find this site particularly useful to begin with, especially for people who want to start prepping over the summer because a lot of the basics get rusty, but as you pick them back up, you can go to Barron’s.
One thing to keep in mind, also, is that you don’t have to be a spelling/accent guru AS LONG AS you can recognize what the tense is given a conjugated verb.
The other thing is vocab. The only advice I can really give is: immerse yourself in Spanish completely. For example, I switched everything (my computer/phone, google account, facebook) into Spanish, and by doing so I naturally picked up new words in the span of a couple days. I also started reading the news in Spanish whenever I want to be updated on current events, and if I need to do research for my other classes, I would try to do it all in Spanish first. This can be pretty time-consuming and overwhelming at first, so starting slow and increasing the volume would be probably be easier to adjust to. Also, READ. I personally read El Túnel and El Principito, and I especially recommend these two books because they are relatively easier and have some basic vocab integrated in them. Some words are also repetitive throughout the text, so you would have a wider range of vocab upon finishing them as well. (Be aware, however, that there are some weird grammar structures, which I suppose are regional, in both of them. So just focus on understanding the text and vocab). Fun fact, one of the practice tests I did in Princeton had a passage from El Túnel, haha. There’s also a list of common vocab in the Barron’s book, and I found them both extremely useful. Make flashcards with all the words–you should know a good 90% of the words at the very least to get a high score, in my opinion. Expressions (eg. llevar a cabo) were a topic I really struggled on in the beginning, and memorizing didn’t really help much, so I think the best way to study for these idioms is, to reiterate, READ, because these things are inevitably included in books. It’s definitely more helpful to associate the meanings of these idioms with an actual sentence and context, so that’s my thought on it. If flashcards work for you though, by all means, just memorize them!
And now, the dreaded listening portion. My two cents: the CD’s from both the blue book and Barron’s were too easy (that or this year’s listening portion was especially hard), so I wouldn’t take a couple practice tests and assume that I’m all ready to go. Still, the listening portion isn’t really that hard. I don’t think the speed is the greatest challenge. In my opinion, the challenge is the vocab in context that can throw you off track in the middle of the recording. When I get listening questions wrong it was usually when I didn’t know what certain words mean, not because I couldn’t figure out what words were being said because of accents or speed or things like that (if that makes any sense), so I think increasing your vocabulary can increase your performance on the listening section as well. A note on accents: you should familiarize yourself with different accents if you’ve never been exposed to them, or else they can catch you off guard completely.
I studied for the listening part mainly by watching Netflix shows in Spanish. I started with subtitles, but I believe that you need to be able to know most of what’s being said (75%) without subtitles if you want to really nail the listening section, especially if the show is translated (not played by hispanic actors/voiceovers are added later on. The speed tends to be much slower when it’s a translated show). You can also try Spanish podcasts (there’s a program called Notes in Spanish Advanced that I found helpful). Each episode is around 10 minutes, and I think there are around 90 of them, so you could listen to one every night for three months (I personally only ended up listening to 10 of them or so, and I think my listening subscore suffered as a result). Last but not least, if you have friends who speak Spanish fluently, try to talk to them in Spanish a couple minutes on the phone each day, about any random thing. This definitely helps.
As for random advice on specific sections: reading part A) is really just vocab and grammar, so know them and know them well. B) is the whole fill in the blank stuff, and a lot of times that’s when idioms or cuyo/cuyos stuff come in, and the biggest thing is to make sure you know what the text is about and how each sentence is being referenced by each question. C) I personally find the easiest, since a lot of answers are explicitly stated in the text; the correct choice either is just rephrased or uses a different word. So even if you have absolutely no clue what a passage is talking about, you can probably still get a couple questions right as long as you can match the answers with the portion of the text. Skimming some of the answer choices might give you a clue as to the main idea of the passage as well.
Overall, the process of prepping for the test was actually a lot of fun for me because I have a genuine interest in the language. I think studying for a subject you’re interested in is much less grueling than for a subject you hate. If you are willing to dedicate a lot of time in Spanish and have been a pretty decent student in the last 3/4 years of high school Spanish classes, getting a high score shouldn’t be too difficult. You really have to establish this sense of routine and comfort level with the language though. If anyone has any specific question, feel free to ask. I know I personally was pretty clueless when I decided to take the test, so I want to be able to help others who might be in the same position that I was in. Sorry for the disorganization and possible rampant grammar errors; I sort of just typed this all in a trance, but I hope this helps!