I am starting to get into making my frames and I have learned to make my own inlays but have not put one together yet, my next frame I will include an inlaid frame. As far as making a frame It depends on what wood thickness you cut your pattern from. For 1/4 ply I start by cutting all the wood for it on my table saw to make sure they are all the exact width and thickness. Next I use my router to cut the groove in for my project on all my frame wood. If I am going to round my edges I route all of them. If I decide I want to have a 45 degree on the inside of the frame I route that next. Then I go to the miter saw and cut my length so they are exactly the same. Because I am new to making my frames, I then lay the first two pieces upside down and check to see if my project I am framing is the precise length I need. I always cut them a little too long on purpose so I have enough for this step. I inside of the the grove where the plaque is going to be inset is where I determine the length needed. I usually allow about a 16th inch total length longer as that will still hold my insert pattern without a problem. I do the same one the other two sides and when I am happy with that, I glue them up.
That is they process I use and it seems to work for me
Dick
heppnerguy