Just because you purchase a shade structure does not mean that your job is done. There are many things one can do to make sure those who are using the area enjoy themselves. The design elements that you will want to focus on implementing will depend largely on what kind of property the structure and patio is for. Commercial, residential, public/education, will all demand different needs and different goals.
Residential properties, mainly meaning homes and some apartments, will want to focus on several things. Firstly, the seating should be mainly closer together, with only a few chairs set apart. The seating should consist of both benches and chairs. Pew style benches will hold far more people for the room they take up, and loveseats are good for a balance between chairs and pew-style. The material for the seating can depend on the style of the house, comfort, and durability wanted. A grated plastic or metal will hold up in extreme weather, but metal will tend to be less comfortable than something plastic. Treated wood also tends to be more comfortable and combines well with certain aesthetics, but will not be as likely to last very long. But regardless of the type of material you use, for residential patios it is recommended to use outdoor pillows. A few tables are also good to create an area for people to gather around, and encourages outdoor grilling. Plants are also something that works great to create ambience. The shading used could be an awning, or to cover more space (if the patio is not attached to the home) a pavilion.
Commercial buildings (offices, restaurants, bars, and more), are going to need more tables, as the guests using the patio will likely consist of several independent groups. Benches can still be used to maximize seating, but the materials that work best will be metal seating to make sure they last. Additional items that complement the patio should be things that cannot be stolen easily. This means that pillows are generally not something that should be used, and any plants should be planted in the ground instead of in above ground pots. Commercial buildings should also plan for cigarette smokers being the main people that use the area, meaning plenty of ashtrays or disposal bins. The visitors are also less likely to care about keeping the area clean, which means you need to make sure you keep it easy to dispose of trash. Same rules for residential for shading, awnings can work great for attached patios. But individual tables could instead use small shades attached to the tables, or for maximum shade you could use a large shade structure to cover the entire area.
Publicly owned areas, as well education areas, should have patios very similar to those of the commercial buildings. It should consist of multiple benches and tables. You want them be to be comfortable and accommodate everyone who may come into contact with them as they will be used by a wide range of people. It is very important to have some form of shade set up with these patio areas as they are often used for resting or relaxing outdoors for a period of time. Also make sure you are using a comfortable material that won’t get too hot and burn someone skin just for sitting on it, but will also hold up with lots of wear and tear.