K.P.
We frequently have sleep issues with our 3 year old also- he goes in cycles of good and bad. When he's in a phase of waking up in the night, we use a reward chart with him and it works so well. The basic idea is that he can earn up to 2 happy faces a night, and when he has earned 10 (or even as little as 5 when you first start), he gets a reward. We have done both earning $5 to buy a small toy and also getting to go someplace special, just to mix it up. Since your son would probably love to have some time doing something special with you, that might be the way to go. If you want more details of what's worked and not worked for us, send me a message and I can tell you more. Good luck!