Craft activities for short occasions

I've been running craft workshops recently.
All of these are easy crafts for youngish (7-year-old and up) children, can be completed within an hour (or dragged out into more elaborate projects as necessary), and don't require a lot of advance training for the facilitator.
I like these crafts because although they are good activities to do with kids when you have an odd 40 minutes to fill, they teach craft skills that are more sophisticated than the average glue-something-to-something-else craft project.

All of these are Google-able for instructions and examples.

1.) Yarn dolls
2.) Polymer clay -- millefiori techniques
3.) Paper quilling
4.) Make candles (roll or dip; I've never tried using molds)
5.) Build forts in the woods, or fairy houses. Or, bring a bunch of twigs into the house and hot-glue them together to make fairy furniture.
6.) Needle felting
7.) Sew tiny bags, turn them right side out, stuff them with rice, and then sew buttons on them: several basic sewing skills in an hour.
8.) Paper marbling/suminagashi
9.) Basket weaving
9b.) also pine needle basket weaving, but you have to have time to boil the pine needles before you use them
10.) Daisy chains
11.) Weaving potholders

12 & 13.) Macrame/kumihomo, and origami. I separate these from the rest of the list because they demand a little more precision, so some kids have trouble with them.
14.) Pysanky. I separate this from the rest of the list because, while it is a kid-friendly craft that is a great way to fill an hour, it involves fire and specialty equipment, and you have to prepare lots of eggs ahead of time.

I haven't tried making temari balls. It really looks like too complicated a craft to be on this list, but it is such a little-known one that I think it deserves mention.

15.) Lemon crabs. This one isn't a craft, just something fun to do while babysitting: twist each corner of a paper towel a little, put a lemon under the towel, and roll the "lemon crab" gently across the floor. The crab-like way it scuttles across the floor is peculiarly charming.