Adding to the Wald bodges - I couldn’t mount one of the front racks due to my brakes being on the rear of the fork, and couldn’t face the wald handlebar mounts.
My set up is a couple of rack struts (from triton cycles) some p-clips (idea from the nitto / blb rack) and some homemade brackets made from sheet metal (you could use some steel fixing plates or could buy aluminium cut to the right size off eBay). Total cost for the bits, excluding the angle grinder was under £20.
I’m really pleased how elegant it turned out and it’s surprisingly strong; I’ve had 5kg in there and no movement. My friend said it was my ‘magnum opus bodge’, which is the highest accolade I’ve ever received.
Also, lomo do a great waterproof rack bag which fits almost perfectly for under £40.