Mark, I select a negative that can be at worst requiring either a single dodge or burn, or at best a straight print.
My current selection which I printed a week ago in 58 minutes, is a single straight exposure.
For an easel, I use a piece of chip board. The flat chipboard has two pieces of timber nailed to two sides that are raised 5mm above the chipboard surface. I simply slide the paper into the corner, expose then change it quickly with the next one. This chipboard easel has paper sizes from postcard through to 12 x 16" marked in a ball point pen. I use this almost exclusively with RC paper. The base has four rubber feet attached, this stops it slipping on my enlarger baseboard
If I was making an easel today I would use MDF, as this material appears to have replaced chipboard, which was all the go 25 years ago when I whacked this easel up.
Like Kate, I find the time taken to hand write the addresses is a bit of a time thing. I tried to pull the file into Excel and print out address labels, but somehow it won't work for me. It's not an issue, I just do a few cards each evening until they are all done, mine will go out this week.