#1 Go with your friends: If your friends are all playing a game, you will likely want to try something on the backlog as well
#2 Mix it up: Playing one genre of games can get repetitive for long periods of time. So I play battle royale shooter for a while, then RTS, or slasher RPG
#3 Number-crunching: Create an excel spreadsheet, list all your back log games and give them scores based on different aspects of gaming (such as visual, story, gameplay, time commitment to finish). Use an average / customized weighting system to arrive at a score for each game. Play the highest scored games first. This is the math approach LOL.