This is an end table I made out of 2x4s and scrap plywood.
Step 1: Materials
Cut out the plywood top and 2x4s to desired size. Also, if you want, you can cut trim to go on the edge of the plywood. The trim can also be whatever size you want.
Step 2: Trim (Optional)
If you are putting on the trim, attach all 4 pieces to the plywood using a nail gun. You can do gaps like I did or do it any way you want. Make sure the trim is flush with the plywood.
Step 3: Sanding
Sand the tabletop and 2x4s from 60 grit to 220 grit.
Step 4: Pocket Holes
Drill 2 pocket holes on the top of the legs and 2 on each end of the supports as shown in the pictures.
Step 5: Joinery
Using the right size screws in the pocket holes, attach a leg in each corner. On the 2 longest sides, attach the supports about 4 inches from the bottom of the trim. For me, screws stuck out of the tabletop. If this happens to you, use and angle grinder to grind them done. You can also use a rotary tool.
Step 6: Finish
Apply a finish of your choice. Now you're done!