It’s often useful to have plenty of loading options on your bike. So when you find loads of food in the dumpsters for example, you can easily take some and be a bit independent from trailers.
It is actually pretty easy to attach a rear rack to the front of your bike. Rear racks can be very easily found in any bike kitchen. You just have to figure out the right size, that it doesn’t touch the wheel. If it messes with your mudguard, you can also just remove it. The front mudguard anyways doesn’t do much.
You need to fix the bottom part of the rack to the lower end of the fork. (Some forks have a hole for a screw next to the axle, that is the ideal spot. Otherwise you might be able to just put the axle through the rack hole.) The most tricky part is the attachment to the center of the fork. Here you can be inventive and build any kind of attachment. Be careful that it doesn’t block the front break from working.
One tip, how to build the attachment is to make a model from cardboard. Just cut out the exactly shape you need, try if it fits (you might want the rack to be leveled, if possible) and if so, cut out the same piece of a thick metal-sheet, at least 1 mm. Then drill the holes, and fix it to your bike. Voilà!
(Michal) Another rear rack adjusted for the front use:
In this case I had to use 2 metal strips, as the flat surface for attaching on the rack has 2 holes on the sides. I used a small L-piece to connect the strips with the fork of the bike. The rack is not leveled perfectly, as I cannot move it to the back enough because of the front brake, though it still works without problems. I had to say goodbye to the front mudguard as there is no space for it. Well, it won’t be missed!
A bike loaded to the maximum!
Somebody else did the same thing: https://pedalshift.net/2014/03/hacking-rear-bike-rack-front-rack/