I use gauze pads, sometimes many, but the bigger the bleed the more you need. I have a few individually wrapped sterilized gauze pads in all my FAKs, but I also carry bandanas and maxi pads in all my kits, not only for their intended purposes but also for big bleeds. (They work great for splints as well.)

I got a pretty good cut this on my thumb webbing this summer, and the first thing I had on hand (LOL!) was my bandana. Worked great for immediate pressure!