You can use cedar or weld something with metal, it is all up to you. Cedar is both rot and bug resistant. Metal will have a greater longevity, but will have to eventually be repainted Do you have a general plan in mind?
Depending upon what material you want to use, that will determine your tool arsenal.
To give tomato plants proper support, maximize sun exposure, reduce plant disease and keep fruit off the soil, a tomato trellis is a great option. You can make your own tomato trellis using supplies from a home improvement store. Here is a list of supplies and instructions for how to build your own trellis for $20 or less. read more