While you may be thinking about building your own patio cover from 'scratch', consider the time savings you could make by buying a kit. These kits are made for the do-it-yourselfer in mind. They are not like legos, but as close to it as you can get with building materials. They include the directions and often certain hardware. You will be responsible for the screws or nails and sometimes brackets yourself. These kits usually include the wood and have the cuts made to your specifications.
You can also opt to buy a pre-measured and put together patio cover kit that just requires assembly. This is the same as the principle above, only in this case you are not actually measuring or planning out your patio cover designs. The reason that these kits are so popular is that they can also be made with vinyl materials as well. These require little to no maintenance, especially when compared to using wood.
Even people that build patio covers for a living still enjoy the ease of using a kit at times. They are sometimes the ones who develop these kits themselves. They see the same cuts, angles, dimensions and materials being used so often that they decide to basically 'automate' the whole thing. It works very well for the wood patio cover, but not for some styles.
Because patio cover designs vary so much, getting the one that you want often requires a bit of customization or personalization. You can still add on to a kit, but sometimes it looks that way. For a truly unique look, designing your own or having on designed is the way to go. With these types of custom patio covers, you can get looks made with stone, tile, draperies, metal roofing, and anything else you have in mind. When you build your own, the sky is the limit. All you really have to think about is building codes and HOA restrictions.
Yes, getting your covered patio is a fairly quick project with the right tools, skills and possibly help, but the look lasts for years. You can realistically get your patio cover built in two weekends. This is more than enough time to pour the concrete (if necessary, depending upon your site), allow it to cure, seal and/or stain your wood (if applicable), and assemble your structure. If you use a kit, you can shave hours off the time by not having to measure, cut and fit your pieces. And, if you get a vinyl patio cover kit, you don't need to spend time sealing your wood. True, patio cover kits will save you time so you can get out and enjoy your more time on your patio.