More sets to increase overall volume/load lifted. Reps - lifting the same weight but for more reps still means you got stronger & worked harder! 
Tempo / TUT - by slowing down a movement and adding specific tempos to eccentric or concentric parts of the exercise (while using the same weight), you're placing the muscle under stress for a longer period of time, and so, working it harder! Try this out on an RDL, lat pull down or Bulgarian split squat and you'll know exactly what I mean! 
Pauses - if you haven't tried adding a pause on the squeeze or stretch of a movement you haven't lived! Haha. No really, it adds a whole new level of fuckery. Some of my personal faves to add these to are; bottom of an RDL, single-arm rows, top of DB lateral raises, leg press, leg curls, I mean the list goes on, just try it out next time you train and let me know how it feels! 
Supersets / drop sets / cluster sets / pre or post exhaust sets - there are tonnes of different set styles you can use to increase intensity & really burn out the muscle. Supersets are a solid choice if you're stuck for time, drop sets are just super effective IMO! Cluster sets allow you to push the same weight for more reps by including mini rest periods within the working set. Pre-exhaust sets were a tool I used a lot when programming home workouts during lockdown & people only had lighter weights available to them. 
Better Technique - think about it, if you lift a weight with proper form it's much harder right? You're going to benefit from proper reps so much more than improper ones. Aim to improve your form every single session - this is something me & all my coaching ladies adhere to.