When I used to make all my furniture at home out of contiboard I would work out the boards I needed and make a cutting list then go to either homebase or B&Q who had a wall panel saw.
B&Q would cut to the exact sizes I wanted while Homebase allowed 2 cuts per board and 25p a cut over the 2.
I had the list worked out so they could cut 2 sheets/planks at a time so I never had to pay any extra.
The most difficult and time consuming part of making furniture out of chipboard was getting the screw holes in the right position.
I used chipboard plugs for screwing into and made a jig with changeable drill bushes for the clearance holes and matching hole for the chipboard plugs.
I didnt have to mark out any holes.
Just used the jig which was designed for use with chipboard with 3" differences in width.
Drill bushes made from old broken milling machine drawbars during lunch break at work.
Hardwood for the jig cost approx £1 for the short lengths required (18") and holes drilled accurately at 3" centres on same milling machine as the drawbars were from.
Pity Plasplugs stopped making those chipboard plugs or I would have patented the design and sold it.
That £1 in wood has saved many hundreds of pounds for all the furniture I have made for myself, kids and friends over the last 17 years.
Kitchen cupboards both floorstanding and wall, wardrobes, TV cabinet, hi fi units, computer desk, huge floor to ceiling 6 door kitchen cupboard, the list is endless.
Good job I realised that those chipboard plugs were no longer being made so bought up everyone I could find and still have a couple of thousand left