Assuming most homeowners will work in wood and not metal due to the specialty tools required for that work, this article will deal with some simple wooden gates.
You can construct your gate from fancy cedar planks, pressure treated lumber, paint grade lumber or just plain old lumber scraps you have lying around. Use your imagination. The more creative you are the more unique your gate will be. If you are keeping cows in a pen, a good strong solid gate is required with no fancy frills.
If your making a gate for your flower garden you may want a fancier dressy gate with scroll work or other decorations. The sky is the limit. Determine first the outside dimension you want the gate to be. Livestock gates may be four feet high by ten feet long or wider to allow passage of animals and a pickup truck with feed. Walking gates in a garden may be only three feet wide and four feet high.
This gate may have a fancy scroll work top or a design cut into the face of the gate just for decoration. Once the outside dimension is determined the basic frame can be built. The frame can be constructed of one inch by two inch lumber pieces, end lapped for strength and glued and screwed together to form a rectangular base for the face of the materials.
The frame generally is on the inside out of the view of the passer-by. I last constructed a gate face from some wood scrap I had in the shed. A four inch by three inch by six foot long piece of old used dried wood with plenty of old rusted nails holes was carefully checked for any nails or embedded metal and then sliced on my table saw into 1/4′ thick strips.
Laying these pieces side by side on the base frame created an interesting visual pattern and cost zero. Using some small headed galvanized screws I fastened the strips to the gate frame keeping the sides and bottom flush with the frame. After completion I scribed a fancy curve on the top of the gate and cut it out with a sabre saw.A coat of white paint if it is to be fancy can be applied or just leave the gate to weather naturally over time.
Pressure treated lumber can be used of course but let it weather a couple of years if you intend to paint it. Fresh treated lumber will shed the paint off very quickly. Cedar provides a beautiful visual effect when left to weather but is not as strong a wood as oak or maple. Cedar is easy to work with and sand but is more expensive.
Whether your gate is to built of wood or metal the basic designs are the same. Use appropriate hardware for the size of gate you built and you will have years of good service from it. Buy a good quality gate hardware set with hinges and latch included and use appropriate fasteners to mount the gate to the support post.