I bought some cheap (10€) digital callipers about a year ago, before that I only had vernier callipers. They are no good for absolute dimensions, but for making knives, where pretty much everything is relative, they work great. I use them all the time, even more so when making folders. When I need to make something more precise, I use a micrometer.
I also use a small hammer a lot - I made a very short, ~12mm handle for it, I use it for everything between centre punching and peening.