I just digitized 50 VHS cassettes a few months back.
Watch any YouTube video about cleaning the VCR head itself.
It boils down to wiping the dust out of two little divots inside the dove silver spinny thing, and every time you play a VCR, The dust gets stuck inside those same two divots.
And after you clean the dust out, the picture is remarkably clearer.
https://www.youtube.com/watch?v=4sGq1CW6AuU
So if you play a tape and you see those horizontal bands of static going on, likelihood is dust has gotten into those two little divots.
So take off all the screws for the VCR housing so you can easily access those little divots, and then every time the static standing shows up, eject the tape, clean those divots, everything's clean. There you go.
https://www.youtube.com/watch?v=4sGq1CW6AuU
Vhs cassettes naturally degrade over time so the best you can do is make sure your VCR is running tip top and don't mess with the VHS tape itself at all.
And make sure that your frame rate and all the tech specs of whatever capture program you're using matches the optimal frame rate/resolution, which is super low for VHS.
There's tons of message boards that go into a lot of detail, but usually if you buy something like elgato they include all that information.
Stick with the defaults, don't increase the resolution past the VHS resolution and regularly clean the divots in the silver spinny thing i can't remember the name of and you'll be golden.
Oh and check if they're ntsc or pal, those have different framerates.