Teaching restarts/set pieces can be difficult to work into your curriculum. At least in your first cycle with your team, I think it's especially important to cover:

goal kicks
corner kicks
throw-ins

These are probably 3 of the most common, so they'll have the biggest on game day. Goal kicks can be worked in when you're teaching your team how to build out of the back. Corner kicks can be worked in during attacking play in the final third. Throw-ins would fit nicely into either of these topics as well.

The second set of set pieces I've found it worthwhile to cover have been:

Direct free kicks
free kicks wide in the final third
deep throw-ins

Direct free kicks take the least amount of time to cover, and depending on how much complexity you want to layer in, could even be covered outside of regular team training. You could simply ID your best free kick taker, give them a couple pointers, and move on.

Free kicks wide in the final third are in a dangerous enough area of the field that it's worth rehearsing them to increase the likelihood of getting something out of them. They're also distinct enough that you need to practice them specifically. Like corner kicks, these make sense to cover when working on attacking.

Much like wide free kicks, deep throw ins represent a distinct, yet repeatable, scenario. Space is limited, and unless you have a player with a long throw, you'll have to get creative to get something out of them. These can also be covered when working on attacking.

It's important to prioritize properly, and I've only started layering in the above scenarios in my 2nd year with my 2006 team. I don't plan on adding any new routines for the upcoming spring season, merely refining the ones we've already worked on.