This is the time of year where it's hard to find time to work with your horse, especially if like me you work full time. By the time you get off work and get to the barn, it's dark, so that leaves weekends for schooling young horses. If it doesn't rain, or snow, or the rest of your life interferes.
I still work with them, there is a lot you can do in the barn, ground manners, tacking, lessons in moving away from pressure, etc. But I also like to leave homework for them to do while I am at work. Usually I leave something for them to interact with, and something potentially scary. One cheap and easy thing to set up is a walk thru obstacle. I found some pool noodles on sale for $1, strung them up at the end of the barn with hay string, and left them to sway in the breeze.
None of the horses had to walk through them, I left the other end of the barn clear. At first they snorted and avoided them. But after a day they were walking through them, and playing with them.
Another homework is walk on scary tarps. I set up a tarp in the field, with poles, and tubs holding down the edges. I then put hay in the center. To eat the hay, they have to step on the tarp.
It helps if a wise older horse dives right into the hay.
Roheryn first snorted and took off when she saw the tarp. Then she had to investigate.
Eventually they all were walking across the tarp to munch the hay.
Best to do this with a tarp you don't care about. They will chew, and paw it so there will be holes.