There are many options when it comes to screws. The right screw offers the better solution to a professional build.
What head to choose?
The type of head that is use impacts how easy is driven into the material being drilled on. Also it matters when it comes down to how the screw is being driven in is it being drilled manually or with a power tool? These are all matters to consider when choosing a head.
What are the types of screws?
Heads provide lots of power transfer between the driver and the screw and choosing the right screw is key. Depending on the function of what is being held together different screws are needed of different materials depending on the situation.
A good example is Sheet metal or panhead screws are useful, when the fastener does not need to be flush with the material (countersunk). Since the head is wider and the thread extends the entire length (no shank), this type of screw head is excellent for joining wood to other materials, metal included.
Which material?
Here the biggest question is whether the screw is for indoor or outdoor use? Indoors, you can use less expensive zinc screws or the material/coating can be selected for visual appeal. But outdoor screws need protection against corrosion from moisture and temperature change. The best outdoor solutions are silicon-coated bronze or stainless steel.
Which size?
The most important factor in screw selection is length. The general rule of thumb is that the screw should enter at least half the thickness of the bottom material, e.g. 3/4″ into a 2 x 4.