Tip 1: Before you pick up lock chest from "Locksmith" save your game. than go get chest and when you dont like the item(s) you got inside chest, reload your game from your recent save slot than pick up chest again from locksmith to get something better.

Tip 2: I always save my game before each auction that way if im not happy with the auction or I spent too much money on it I can get my money back and redo another auction.

Tip 3: If your storage at house and/or shop storage is full I always make sure i have my truck full of items before i go to sleep so to sale to pawn shops at 9am next morning.

Tip 4: Before returning home for the night make sure your truck is full of gas and that you collected your money from your pawnshop.