Cut the legs to size and shape. Lay the legs on the floor with their top ends up to the previously outlined support rail in their proposed positions. Using a straight edge, check the bottom of the legs are in alignment, then mark the leg crossing intersection on each leg ready for the half check housing. Mark out the housing depths. These should be half the thickness of each leg.
Remove the housing waste using a saw and chisel. Prime paint the housings. Prime paint all the joints before fastening together. Tack together the legs with two nails to temporarily hold the shape and screw fasten both to the support rails with 2 or 3/57x8g screws each end. Then screw join the legs together at the housing using 2 or more screws. Attach both pairs of legs in this manner.