An exacto (hobby) knife or a small utility knife usually work fairly well and are fairly easy to hold safely - use a hard wood (plywood) or plastic surface such as a kitchen cutting board under the gasket paper to support it. Mark out where you want the hole and then use a round object such as a socket (various sizes up to 1" can usually be found in your tool box, lid off a paint or aerosol can, roll of black tape or use a compass from a geometry set for larger size holes) to get a nice round pattern to follow. Don't apply too much pressure on the first time around the hole and this will give you a groove in the gasket material the knife will follow - work your way around the circle a few times with the knife and it should give you a nice round hole. On small bolt holes you can use a short piece of steel tubing (brake or fuel line depending on the size of hole) - once you cut the tubing to a short length (4" - 6") use a small round file and sharpen one of the ends at the edge so it will cut the gasket material and then use a slow speed drill or tap it lightly on the end with a wood mallet - turn the tube a little bit and tap again - after the tube has been turned around to a few positions the hole should be created. Take a screwdriver or punch and push the piece of gasket material that is inside the steel tube out before you start to cut another hole or else you will have a tube full of gasket material that will be hard to push out as they will stack and bind. If you had a hole saw kit you could try using them by hand as they may work as well.
Most gasket paper comes as a roll which can be a pain to keep flat - a few spring loaded clamps and a flat piece of plywood or stiff cardboard will hold the gasket material flat while you lay out your gasket as shown in the picture.