I love activities that have minimal prep, easily available and low cost materials, with maximum attention and long term gains. I've absolutely no time for intense preparation nor pretty set ups, and no money to invest in certain special equipment. Simple scissors practice activities are so easy to prep, you can use scraps that you've recycled and the good thing is that it really goes a long way.
First I started Nat off with Scissors Practice for Preschoolers from Playful Learning. Look so simple right? But he had loads of fun. Nat has been using normal scissors ever since he was young. The child safety scissors usually don't cut well and children get frustrated when things don't get cut, as do adults! I think it's perfectly fine to use normal scissors as long as there's always adult supervision. In my experience as an art teacher with preschoolers, I've never once encountered a kid injuring himself/herself with the scissors as long as an adult was around.
Another time, we moved onto Developing Scissors Skills with A Cutting Tray from mamapapabubba. Nat cut a variety of interesting stuff that I've recycled: straws, scrap foam sheets, scrap aluminium foil, scrap string. He loved cutting the foam sheets the most. He can actually sit at the table for 20 minutes just cutting and cutting. After you're done with cutting, just pack all the cut up stuff into a ziplog bag and use them for a collage activity!
Nat likes cutting so much and is so good at it that once in a while he will take the initiative to ask for the scissors and just spend time cutting random scrap paper. That's what I mean by the activity going a long way :P