<p>Is there an appropriate limit to the number of recommendations you can ask from a teacher ever? At one time? Is there an appropriate amount of time to wait between asking for each letter of rec?</p>
<p>Thanks.</p>
<p>It'd probably be better to ask for all of them at once. I think most teachers will use the same rec for all the schools, but change a few details. The earlier you ask the better, because that will give them more time to do it.</p>