To build up competency in techniques, players have to do drills. It's through drills that you build muscle memory

The way I used to run drills would be that I would have the players do the same technique over and over again until a certain number of repetitions are completed. And that would constitute one set. Then their training partners would do a similar set. Then it's back to the original player to do yet another set of the same technique. Once three sets are completed for each player, they would then move on to another technique.

Recently, I decided to mix things up a bit, for two reasons. Firstly, I read somewhere that when you give people repetitive tasks, and you have them do a different thing with each rep, rather than the same for the entire set, they learn better. Secondly, it breaks the boredom of doing repetitive tasks if they are doing different things within the set rather than the same thing over and over again.

Now, I don't know if it's really true that learning is better when you mix things up a bit. Maybe it's fake news. But even if it's not true, I don't think there's any downside to doing it that way. As for making it less boring, that is definitely true. When judo players are able to do different techniques, their attention spans increase and their mindsets remains fresh longer.

So, nowadays when I do advanced training for my players (which involves a lot of drills), I try to mix things up quite a bit, not just within a set of drills but I also try to have tachi-waza drills follow newaza drills, and so on. So, rather than have them do several different sets of newaza before moving to several different sets of tachi-waza, I would do newaza sets, tachi-waza sets, newaza sets, tachi-waza sets and so on.

I find that this approach works well. The players remain alert and fresh much longer when it's done this way.