OK, simple fork frame...
Get some 3by3 or 4by4 angle iron,1/4 or 3/8 thick. I used 4by4by 3/8( brick lintel support for houses....)
measure the 'pin to pin distance on your loader and then cut 4 pieces, 4" longer.
if pin to pin is 12", cut them 16 inches.
drill 2 holes in each piece for the mounting pins to go through
remove bucket, raise loader up to nice working height, and install the 4 pieces
place the 'top rail' onto the 4 pieces and tack weld. from the left side, it'll look like an 'L'
remove and weld 'lower rail' same way.
install, test fit, if OK, remove and really weld it.
remove and add 'ends' between top and btm rails.
this is now the basic 'frame' and strong like bull.
it will lift 1800# pumpkin....BTDT.
now option 1, use forklift forks (they slide on that top rail ) or option 2 make your own forks
if it's a small tractor, 36" forks are a good size..keep you out of 'trouble'
if you make your own, look at what dealers are offering and copy.
The hardest part is drilling the 8 big holes for the pins. cutting/welding is easy !
The frame shouldn't be wider than your bucket or tractor.