If you're just getting started, check out this video for a quick summary of what you need to know, then read on below for more details.
In a standard installation, when we marry the male and the female bracket, we need to exercise a slight up and down motion when coming in at a 15 degree angle. This is necessary since you cannot slide them together straight on. The up/down motion however is minimal but necessary. When using the steel bracket you can slide them in without having to perform the 15 degree up/down motion due to the bracket's slope.
However, this means that a 45 Degree angled shelf is impossible to install with having a bracket on both sides. (Left sided or right sided) since the additional bracket side would disable any vertical motion and thus block the components from moving into proper position.
To get around this, you should choose the longest side, (if sides are equal choose the one which has the most advantageous stud situation) and use the Hovr bracket on that side. The shorter or other side gets a screw through the shelf into a stud. Or you can support it by screwing in a piece of wood 2" long underneath that side into a stud. You may want to also consider routering out a void as long and deep as the 2" piece of wood and laying the other side on that.
This void then has to be plugged by gluing a piece of wood, and needs to be sanded down after installation. You may be able to use that piece of wood that you have left after making the void.
That void needs to be exactly on a stud. Now you can use a small female bracket piece (maximum 2 inches long) that fits that void and screw it onto the stud. In this case, and only in this case, are you allowed to cut the female bracket along its length. But not too high, you still want to have room for the screw.
If you need to use a bracket on both sides, it will be always 2 shelves - either with a butt joint or a mitered joint. In order to keep them as one, you need to join them at the bottom with a biscuit, dowels, an L – bracket or a simple screw.
If the shorter side is not more than 15 – 18 inches and the Hovr bracket is installed very close to the wall, no extra support is needed.
Check out this video where Todd explains some things you ought to consider to install a free floating corner shelf: