DO test how your frame hangs before you give it to the gallery. A simple test is to hold the frame by the wire on the back away from the wall without supporting the bottom. If the frame leans forward at an angle, then the mounts for the framing wire need moved closer to the top of the frame.
DO place the hanging wire or gummed fabric tabs with metal eyelets no lower than 1/3 of the distance from the top.
DO use consistent frame styles and sizes. Pick a frame style you like and run with it. Clean uniformity of frames allows the audience/participant to focus on the work.
DO try to use an exhibit framing service. When you are framing multiple works in quantity, find a framer who serves artists directly. They have special frames and rates that are 33% to 50% the cost of normal custom framing. A good curator or prolific photographer/printmaker can usually recommend several exhibit framing services. Exhibit frames are simple, stack well, and ship well.
DO use metal or wood frames.
DO use framing wire thick enough for your frame weight.
DO NOT deliver unframed artwork with no hanging wire, no tabs, or both.
DO NOT use bulldog clips to hang anything unless you are exhibiting grade school art on a bulletin board.
DO NOT use adhesive plastic hanging tabs to hang work.
DO NOT have multiple frame styles and colors for a single show. This is both embarrassing for you and the gallery.
DO NOT use poster frames from the dollar store, or any frame from a discount store unless it is integral to the theme of the show.
DO NOT use clip frames. They may be cheap, but almost never hang level. They fall apart under their own weight, shatter randomly, look bad on all hanging rail systems, and degrade the merit of your work.
AVOID FLOATING FRAMES. Yes, floating frames go with everything, but also tend to show the hanger in the wall behind them and hang poorly when using a hanging rail system.
DO NOT give a gallery artwork that has no means for hanging on the wall. Galleries do not like getting images mounted on poster board with blank backs and being told to sort it out. This is a recipe for disaster.
DO NOT make the hanging wire so long that you can see the hanger and the wire peeking out above the frame edges.
AVOID LAVISH FRAMES AND GARISH MATS. This is only acceptable if you are showing classical works pre-19th century art, or it is a component of installation art.
DO NOT use plastic frames.
DO NOT use polyurethane foam mold injected frames. These frames are usually large and surprisingly light. The weight always gives them away. If a frame seems too light for its size, then do not buy it.
DO NOT mount hangers on cardboard backing. Many poster frames come with hangers mounted in cardboard. This is like nailing a paper grocery bag to the wall and expecting it to hold food.
DO NOT use fishing line, twine, kite string, copper wire, or floral wire as a substitute for frame hanging wire.