This would be a good place to share helpful strategies for those starting out! I've got a few tips I'll share off the bat:
Thugs! Their guard feature is handy, but upgrading your gangs can be the difference between winning and losing in close games.
Traps from the Saboteur are extremely useful if you can get them early enough to deter your opponent from scouting around the map. Depending on your starting buildings around you, an early Saboteur can make for a pesky early game.
Assassination Contracts can be the easiest to get, but be sure to be smart about how you "earn" those victory points. Don't let an injured target stay alive if you can help it.