Now that winter is here, mud conditions are looking excellent, but they do make the bike -and you- dirtier
Someone in the bike shop had this little home-made mini-guard for front suspension bikes out of an old inner tube.
It looks like you take one old tube, slit it sideways to make it wide, then wrap it down from the crown to the crossbar of the lower fork bits and back up again, with cable ties to hold everything in place.
Whether it is any use or not is not known to us. Proof -with photos- that it works welcome. It probably stops some of the water the wheel lifts up from going into your face, but that's about it. It is cheap if you use a punctured inner tube with too many patches to be considered worth repairing again, and should adapt to the suspension nicely. Worth a go.