Pick up some skirting from the hardware store. Measure the shape you want your frame to be, then use a handsaw and mitre block to cut the pieces to size. (A mitre block is a U-shaped wooden tool with channels for sawing on 45 degree angles.) Or get the hardware store to cut it for you.
Apply a small bead of wood glue to each corner, line up edges, then drive a nail into the thicker part of the timber. Do this on all four corners. Turn frame over and on each corner screw in an L-bracket.
With the help of a spirit level, hang your frame using hooks or 3M Command adhesive strips.
Note: Wall brackets for flat-screen TVs are available from electrical retailers.
Team mustard yellows with petrol blues for a scheme that's fresh and modern. A strong striped rug helps balance the dark TV.