Well, that is what I typically use them for (mashed). But I thought they might hold up for something like a potato salad, as they tend to be a bit waxy.
I’m still trying to wrap my head around the concept of “crisp” boiled potatoes.
I tend to find fries to be rather mushy, myself.
I was hoping the OP meant “firm”.
Put 'em in raw.
Turn on some salted water. Scrub potatoes. Don’t peel, leave the skins on. Depending on size, cut in half or quarters. (You want big chunks.) Drop in boiling water and let cook about ten minutes or so, till there’re about half-way done. Scoop out of water onto a cutting board to let them cool enough to handle. Then the skins will mostly slip off with a minimum of peeling. Cube into size you want. Here’s where we put them in a bowl and pour some melted butter over them with some celery seed and S & P. Let that sit about an hour then add your other ingredients.
This! Shocking them in cold water is the way to go. I start them in cold water, and start forking out individual pieces to eat as soon as the water starts boiling. Once they are the consistency I want I immediately take the pot over to the sink, dump out the hot water and replace with cold water. Let them sit in the cold water for a minute or two and you’re good to go.
Try Ruffles! 
Use canned whole potatoes, cut up. They are firm but cooked through, and don’t turn mushy in potato salad.