If the pictures are small and equipped with a wire on the back use a small picture hook and nail.
Hanging pictures on lath plaster wall.
This system works by simply installing a rail along the wall and pictures then hang from cables attached to the rail and are fastened with hooks.
Adhesive picture hooks are the best way to prevent damage when hanging a picture but pre drilling the hole will usually prevent cracks and chips from forming as well.
The ideal solution for hanging pictures on plaster is to use a picture hanging system like the all in one click rail cable hanging kit.
Screws and screws with masonry anchors for heavy items are your best choice for hanging things on plaster walls without picture rail.
The best option mostly depends on the weight of the picture in question.