[GISer3546]

Easiest method would be pocket hole screws, which will offer a good joint. Personally I try to stick to wood joinery, mortise and tennon mostly. A tight fitting m & t will probably be stronger than screws but would require some chages to work with the 45 degree joing you have. In my experience theyre a little better at hiding mistakes and can be done easily with a tablesaw, bandsaw, or a hand saw with a spine.

 

[GISer3546]

Be sure your edges are square and as smooth and straight as possible. Usually done with a plane for the best joints. Screws aren`t needed in my opinion. Usually the wood breaks before the glue does.