Often I use router bits to cut cope and stick joinery to build smaller cabinet doors. The advantage to this method is they are easy to cut as long as you have a basic cope and stick router bit set and a router table. The other advantage is that cope and stick allows you to cut a profile on the inside of the frame - the rails simply have the reverse image of the profile cut into them to receive the stiles. The disadvantage to this method is you need specialized router bit sets, which can be expensive. Secondly, the long grain glue surface is limited to the small stub tenon or "stick" at each joint. For many applications, especially for small doors in casework like this project, cope and stick is a good choice. However, the plans for this particular sideboard call for simple square cut rails and stiles so a stronger joint - haunched tenons - can be used in this case.
This episode is a bit longer, but details the entire process I used for cutting these odd looking joints. But I can assure you, the amount of long grain glue surface the haunched tenons provide ensures these doors are nearly indestructible. My process consisted entirely of power tools (except for some fine tuning of the panel), but hand tools could just as easily give good results. I found with power tools, the process is highly repeatable, so if you need to batch out a number of doors, you could do so with ease.