One good general-use strategy is to place overhead patio heaters at the open side of a covered patio and face them back towards the building, providing radiant heat from the side where there is the most radiant heat loss.
However, if you have fixed furniture, it may be more effective and important to spot heat the furnished areas.
In some cases it is best to mount the outdoor heaters down the middle of an area pointing straight down. While radiant heat coverage is somewhat reduced by this, it does allow for the lowest combustible clearances from the ceiling with gas patio heaters. Some electric patio heaters can be flush-mounted into the ceiling, when pointed straight down, getting them out of sight.
The advantage of placing patio heaters at the house and facing out is that you are not looking at them as you look out. But keep in mind that placing outdoor heaters there will result in unbalanced heat, as you are providing radiant heat from the side of the patio with the least radiant heat loss.
Don’t place outdoor heaters over outward-opening windows or doors. One house on fire can wreck your whole day.
If your patio is more than 12’ wide or so you may place patio heaters on the outside and the inside of your patio, ensuring balanced heat.