Cleaning, lubrication, and a little TLC! Multi-use lubricants tend to do the trick, however, leading speed cube brands usually offer their own lube too (e.g. the GANlube). Here’s a how-to article on speed cube maintenance, however, I’d personally advise getting in the rabbit hole yourself and devouring YouTube videos and tips from the pros because - to no one’s surprise - it’s a bit of a science!