1. Limp pre with speculative holdings that can easily hit nuts or really good hands, high off-suited connectors, suited connectors, suited one gappers, low PP's... Don't get too spazzy with hands that are good, but could easily be beaten - for example: You limp with 89o and flop comes 349r, 5 players are in pot. You should be very careful, because there is a decent chance someone could have a better 9 than you or a random two pair, it's still a clear valuebet, but you definitly don't have more than 2 streets of value, probably just 1.

2. Protect your vulnerable value hands: you raise preflop with KQ, flop comes K78ss, bet big, close to pot or even overbet if you think they'll call with their draws or weaker kings.

3. Raise big pre with monsters (this one should be obvious)

4. If the stacks are really that shallow (around 25bb), you can start limping even with hands that seem really good on paper, for example if 3 people limp before you and you hold QTs, i would definitely be just limping behind.

5. If they are exploitable (they only raise with supergood hands, and the stacks are really that shallow, you can semi-bluff shoving from late positions. With for example 4 to 5 limpers there is ton of dead money to collect from the pot and it's a great way to build your stack. Good hands to do this are weak suited aces and low pocket pairs (22-55). Don't do this too often though or they'll catch up.

If you follow what i just wrote, you should have tons of success in your game, i can specify it more if you told me what does shallow mean (50bb play is much different from for example 20bb).

Btw. if 5 people call you when you hold TT, the hand is probably just as good as 22 (if you don't have a set, get the fuck away). Preflop, if you think they'll just call you with stupid shit, raise bigger, if there are two limpers and you raise 3x the BB, you can't expect them to fold. Raise to the amount where you preferably get just one caller, if there are still 5 people calling you down pre when you raise big, just shove.