When I first tried shooting star trails, my SD card was pathetically slow to save the files.
So much so, I could trigger the next exposure, and the camera was stable before it shot the next frame.
Crude to say the least, but we all start somewhere.
Then I got a wired remote release, Better, but not really there yet.
Then I got the fastest/biggest card recommended for my DSLR. Woo-Hoo, now we were cookin! Storage speed jumped up dramatically.
Then I got an Intervalometer. Hotcha-kookaratcha! Set it and walk away!
Then I thought I lost my wired Intervalometer.
So I got a new one that is wireless. Oh so slick! Able to run it from inside, even in my underwear.
Or from my sleeping bag in my tent.
Then found my lost one buried in the bottom of my camera back-pack. (Recycled from the SIL)
But a 5 second interval has always worked good for me. Plenty of time to reliably store the image. Plenty of time to reset everything. And a reliable interval to calculate my spans.
25s exposure + 5 second interval = 30s segments. 2 per minute, all night long.
15s exposure + 5 second interval = 20s segments. 3 per minute, all night long.
10s exposure + 5 second interval = 15s segments. 4 per minute, all night long.
That leaves me with my ISO choices, which are next to none. 1600, which is too dark; or 3200 which doesn't work great either, or 6400 which isn't good either.
But if I use Aperture Priority Mode, the Intervalometer merely sez, "Go." and the camera takes the shot. I get best consistency with that, with my entry level DSLR.
Which for me works pretty good. Much better than manual.
Since I'm not looking to fiddle or twiddle hundreds to thousands of pictures, I save in jpg because it's small, fast, and ready to eat...
Startrails doesn't stall, and Movie Maker can take 100 image bites without setting there scratching its derriere. Or stopping entirely.
(All night runs can amass >3000 images. I can't wade through each one. Or I won't, is more sincere.)
Typically, I break the images into 100 image folders to work with (after the fact).
I typically use a battery eliminator for my camera if there is 120 VAC available. And the Intervalometer runs for days on a pair of batteries. (2 - AAA)
I would do more, just because they are fun to run. But when I can amass thousands and thousands of shutter operations a night... well my bottom dweller camera isn't going to last forever.
One other item I like having is a geared head on my tripod. Makes fine adjusting for framing a snap.