Your timing is near perfect for D1/D2. You will want to get on their radar early summer.
Select at least 10 schools you are interested in and email the coaches. The email should be all quality (negative points for quantity). Put your name in the subject line.
The best advice I got is this: Write a first sentence that nobody else can. (and keep this mind for college apps, job apps, etc..
Round out first paragraph by mentioning TRN or USTA rank and maybe a good recent result. Next give them a schedule of tournaments that you will be playing should they be able to watch you. Add a short paragraph at end noting your academics, sportsmanship awards or other info showing you are a solid citizen. Would also be good to mention team experiences (in tennis or other sports). But again, assume they have a very short attention span while reading email so hook them and give them just essentials.
Close with a little info that personalizes the email a bit (reference their conference or someone you know who plays/played for team or their school mascot...). Include your coaches name and phone/email who they can contact - because they can call the coach but they cannot call you or return calls. Sign off by saying you will call/contact them in the Fall to see if they think you'd be a fit and if they have interest.
Target this intro email for early summer when they are thinking more about recruiting vs now or spring as they are in middle of their dual season. When you call them in the fall, email them a time that you will call a day or two in advance. If you get answering machine, again, leave a time you will call back on your message. Remember, they can't return any calls or emails. I'd say if they don't pick up phone after two or three tries (when they knew you'd call) or try and contact your coach after you've called them, then they aren't interested.
Lastly, believe me, an interested college coach watching WILL notice sportsmanship, mental and emotional composure, fighting spirit, grinding in backdraw, seeing how you interact with opponents and how you get along with players while hanging at the site. This and proven team expirence may be the 'tiebreaker' when considering similar abilities vs other potential recruits.
(and to goran's point....yes, this is from experience...)