Step 1> Get your pallets for free from waste disposal companies, allotments ...
Step 2> Get 4 bricks and some flat board for the bottom, drill drainage holes
Step 3> Get some compost and fill the pallet gaps
Step 4 > Seal the sides by screwing some side panels to lock in the compost
Step 5> Water thoroughly until the compost settles, then top up some more compost and finally sow your seeds!