Looking for help hanging a framed painting on wall

I need a skilled hand to hang a framed painting securely on a plaster wall. The frame is about 60x80 cm and light to medium weight. I’ll provide the wall space, mounting hardware, and level, but I’d appreciate guidance on the best type of wall anchor for this wall. Please bring a stud finder, drill, level, and appropriate screws. I’d prefer a neat, professional finish and to avoid damage to the paint. Location is in London, and I’m flexible on timing within the morning.