Are your workouts getting stale?
How about some friendly competition with your training partner or even yourself? Most people will never enter a bodybuilding contest or a powerlifting contest, but contest training is a great motivator.
Pick a date, 8-12 weeks away and set a goal. It could be squat “x” amount of weight, most fat lost/most muscle gained, it doesn’t matter. The date you picked is the deadline for the contest.
What’s the prize? If you have a training partner, each of you will put $1 a day into a fund for the ‘contest’ prize.
If there are two of you that can be almost $200 after twelve weeks. At the end of your selected time, have your contest. Whoever wins gets the prize.
If you train alone, do the same thing, but if you don’t succeed, the money stays put in the ‘fund’ until the next contest with yourself.