PNTYNSPLT,
I am in a similar situation (4 yrs out). Advice I have received so far.....

1. As Shaggy said above Network...Sit down and list every single person you think might help you and contact them. Three years is plenty of time to rekindle (continue) your relationship with them. Bottom line - you never know who can help you...ask around. I am FTS (TAR) and the SELRES are some good people to be close friends with...they know you and know people who know people.
2. Start fixing your log book now. There are plenty of programs available to convert them to an electronic copy. Those AZs don't care if you get hired so start checking their work. 4000 hours of fighter time is a fair amount of hops so there is bound to be a few mistakes.
3. ATP and type ratings (if desired/needed) as you can get them.
4. Since application windows open and close odds are they will be closed when you are ready to apply. Pay the fee and put them in now. Update your availabilty date and hours as you get closer to being ready. Some say the original app date shows how long you have been interested. I can't confirm this but Murphy says do it now because he will close the window when you need it.

Good luck---Keep in touch.

Boyd