Depending on the type of plants, most times I use my finger nails or fingers to pinch them off and re-plants. On the more woody stemmed plants like my hygrophila I use a small pair of sharp dubbing shears. I also use a small pair of nail scissors on the more delicate plants.
The scissors I use are clean and only used in my tanks now.
I did buy one of those long handle planting things that has a scissor attachment (cost less than 20 bucks), but I found it easier to just use my hands/fingers for most of it and never use it any more except to grab snails to remove...lol....