Just use common sense. It's definitely going to hurt for awhile but you don't have to play until you draw blood. Your fingers need time to heal and grow new skin and your brain needs the time to absorbe new material.

If you start doing it now, you can get pretty good at just playing solos in your head.
Try it a few times on the guitar until you've got the basics down, then go & sunbathe or something while you play the notes in your head.
Go back to the guitar later that night and suddenly you know the lead and you didn't have to do anything.
Works good for writing leads too. Play some background music, then go lie down and let the music run around in your brain like a song off the radio that's gotten stuck in your head. Spend all day trying to remember what the solo sounded like and your subconsious ends up writing lead lines for you.

... was that too spacey for an answer?
I've been up for about 36 hours and I'm getting a little punchy.