Hey Diane, here’s what I do. I play multiple instruments so this really helps me a lot. I’ll also outline a typical practice session for me and what I teach on banjo.
I first do a slow warm up. Here’s the fun part. Grab some good old index cards. Punch a hole in the corner of them and put a ring binder thing in the hole. Then write 1 song on each card that you know. When I say “know” I mean you play it by memory and no tab or sheet music. Let’s say you really know 10 songs well. Then during this 10 minute warmup (or however long you use for a warmup) you play the first card (song) once through slowly. Then flip another card and play the next song. Do this slowly and if you mess up or can’t remember any of it, continue playing it through until you get it right, but keep it slow. Next practice session you pick where you left off in the stack. Let’s say you go through 2 or 3 cards each practice session. Then over the course of the week of practicing you’ve done went through all 10 of your cards and kept those songs fresh. Continue to add cards as you learn a new song fully. Try it out, it’s fun, and you don’t have to think about it too much or worry about “losing” songs. If you decide you don’t particularly want to keep a certain song, then chuck that card out in the trash and move on. Sorry to be long winded but that’s a great warmup that will also keep your songs fresh. *Not my idea by the way, I read this years ago somewhere and started using it.
After warmup, normally I have folks work on techniques. This can be done using a song, a certain section of a song, chords, scales (if so inclined), or short pieces. I also have them drill sections here that are sticky and a little tough to complete up to speed. This would also be where we use a metronome (if we are using one at the time).
Next I have them working songs. Usually we have one we are currently on (learning) and one we start with. So we are normally working on 2 songs at a time and some technique. May or may not use a metronome here as well depending (or a drum track, or something fun like that).
Then the last bit is always reserved for FUN time. Anything goes here, anything that makes you smile! Cut loose and have a blast playing your dulcimer.
I ask people to devote at least 30 minutes per session, 4 times a week. Me personally I play a LOT more than that though, LOL because all of it makes me smile.