Here is a repost from 2009 on my rebuy strategy:
I SUGGEST READING THIS WHOLE POST IF YOU WANT SOME REBUY STRATEGY FROM A SUCCESSFUL REBUY PLAYER!!!!!!!
I have done very well in rebuys and they are A LOT easier to cash in than a normal freezout.
My strategy is this:
1) During rebuy stage, once there is one player (yes just one) who has used a rebuy or if there are any players with well over 1500 chips, YOU MUST REBUY! So 9 times out of 10, you are rebuying right off the bat before you see a hand. This is the same idea as always having the max buy-in at a cash game, you want to get max value when you hit a big hand.
2) See cheap flops, also if you find people raising a lot preflop with anything, pick a hand and come over the top and try to double up. Even if you think you are only 60/40, still come over the top and go for the early double up. During the rebuy period you want to take shots, because you can always rebuy and try again.
3) DON'T PLAY REBUYS IF YOU ARE SCARED TO REBUY.
4) Once you are about 10 mins or less away from the break and the end of the rebuy period you need to look at a couple things. If you haven't doubled up and are at 4000 or less in chips you want to start pushing every unraised pot for a chance at a lucky double up. Seriously, yes. The reason is the blinds are usually 50/100 at this stage and if you continue to play tight you will probably head into the break with 3400ish in chips. If you take those chances you will steal some blinds and maybe get a call, where you will either double up or bust and just rebuy back to 3000. So TAKE SHOTS LATE IN THE REBUY HOUR and DON'T BE AFRAID TO REBUY!
Now if you have a healthy stack of lets say 6000+ you don't want to take as many shots but still keep this concept in mind.
5) ALWAYS ADDON NO MATTER WHAT!!!!!! Some people say, "I don't addon if I have a big stack, there is no point." You most certainly have to addon in every single rebuy tournament you play. I see people refuse the addon so much and it boggles my mind. Obviously the goal of the tournament is to win, but you want to try to save 1 buy-in when you win??!?! If somebody who won the big $3r on stars without adding on, would they feel amazing about the $9,000 or whatever 1st place is, or would they feel amazing that they "saved" $3?!?!?! It is so crazy not to addon, yes even as chip leader, you need to addon.
6) With my rebuy strategy I average 3-5 buyins per tournament. The initial buy-in plus 1st rebuy and the addon. And occasionally I have to double rebuy if my big hand doesn't hold up or if I am getting low near the 1st break I will take some chances and possibly have to rebuy there. So according to my BR management I take the buy in of the rebuy and multiply by 4. If that is still less than 2% of my roll, I will play. (ex. $5 rebuy x 4 = $20, if I have a $1000 BR or higher I can play $5 rebuys)
A benefit of rebuys is a minimum cash is about 6-7x the buyin, so if you did decent and only are in for 4-5 buy-ins, you are doing good. Plus, a lot of people do not rebuy, so what this does is it essentially makes the 2nd portion of the tournament a deep stack with a very easy shot at cashing. (ex. The $5r PLO tournament on cake at 12:30 EST gets about 200 entrants. Once the rebuy period is over there are around 70 players left and cake pays top 40. If you played my strategy correctly, you are usually in a spot to cash even with just a modest stack.)
So yes this is a long post, but if you want to succeed at rebuys I HIGHLY RECOMMEND this approach. Again, I have done very well with rebuys and they are my favorite game to play!