I’m a fourth year undergraduate.
Might it be good to take a year off before graduate school, to gain some life experience?
Yes, it is. As someone who did not take a break between college and grad school, I am a huge proponent of taking a year (or two or three) to do something besides education, and confirm to yourself that you really want the career you want to go to graduate school for.
I took a year off, and it allowed me to craft a stronger application. My transcripts were complete to the end of the year, and I had finished strong. I. I contacted faculty for recs during less busy times of the year and I think that they were stronger and more complete than they might have otherwise been. I had time to review for the GRE and certainly scored better than if I had taken it during the school year. I had time to visit prospective departments and meet with faculty. This made it easier to write personal statements making the case for my fit and contributions to the dept. I enjoyed working in the real word and relaxing a bit. I had time to read lots of books that are interesting to me, not just assignments, sharpening my sense of what direction my grad work would go. And I arrived at my grad program refreshed and eager rather than in a rut and burned out. I did 2 more grad degrees after my first Master’s and took a year off after each one, repeating these benefits each time. Best wishes for the process!