Here's a straightforward approach:

**1. Check the frame's weight and hardware**
- Look at the back: sawtooth hanger, D-rings, or picture wire.
- Light (<10 lb / 4.5 kg): a nail or adhesive strip works.
- Medium (10–30 lb): use a picture hook rated for the weight.
- Heavy (>30 lb): find a stud or use wall anchors (toggle bolts for drywall).

**2. Pick the spot**
- Center the picture at about **57–60 in (145–152 cm)** from the floor, a common gallery standard.
- Over furniture like a sofa or bed, leave 8–10 in (20–25 cm) between the furniture and the frame's bottom.

**3. Mark where the nail goes**
- Measure from the top of the frame to the hanger (pull wire taut toward the top if it has wire).
- Mark the wall at your target height plus half the frame height, minus that hanger distance.
- Tip: put painter's tape on the back across the hangers, mark the hanger points on it, then move the tape to the wall and level it. It's especially handy for two hooks.

**4. Install the hardware**
- **Drywall:** a picture hook nailed in at a 45° downward angle holds surprisingly well. For heavier items, use a stud finder or an anchor.
- **Plaster:** put tape over the spot first to reduce cracking, and pre-drill a small pilot hole.
- **Brick/concrete:** you'll need a masonry bit and plugs.
- **Renting/no holes:** Command strips or hooks, within their weight rating.

**5. Hang and level**
- Hang it, put a level (or phone level app) on top, and adjust.
- Two hooks spaced apart stop larger frames from tilting.
- A small bumper or bit of putty on the bottom corners keeps it from shifting.

**Tools:** hammer, picture hooks/nails, tape measure, pencil, level, and optionally a stud finder or drill.

If you tell me the frame's size, weight, and wall type, I can be more specific.