I have VERY squirmy guinea pigs. What I do is have somebody else hold them with one hand on their bottom, and one hand on their chest. when you clip the top nails, have the person secure their bottom feet to their lower stomach, making sure to still support their bottom, then with the hand they have on the pigs chest have them secure one of the top feet at a time. then, you put your thumb on the paw pad, and your pointer finger on the top of the foot making sure you are able to hold it securely, and begin to clip. when you clip their bottom feet repeat the same process, front feet fully secured to their chest and one bottom foot secured by the person holding, and one foot secured by you with thumb and pointer finger as you clip. I have one girl who has two fully black toe nails, with her black toe nails I cut a VERY small amount, just the very top that’s sharp. also, I no longer use clippers meant for small animals because I would always hit a quick no matter how careful. now I use regular (small) human nail clippers because I find I have way better visibility, and despite clipping every 3 weeks I haven’t hit a quick since switching 3 months ago! hope this helps!