We've been keeping a list of our favorites; if you've just picked up a set for yourself, give some of these a try when you're ready to switch up the standard farmer's walk!
Ok, we'll start off easy. Instead of using a matching pair, try mixing Love Handle diameters during your farmer's walk. You can keep the loads equal between them, or do a heavy weight/smaller handle and lighter weight/larger handle. Alternatively, you could use a Love Handle in one hand and a kettlebell in the other. Switch hands depending on your rep scheme--you could either do it between sets, or do it as needed (particularly if going for distance).
Use a fatter-than-usual handle (usually a 2" if you have small hands and a 3" if you have large hands) with a moderate-to-heavy weight, depending on the distance you plan to go. Switch freely between both hands as needed--trust us, by the end of it, they'll both get plenty of work done.
A personal favorite. Using cones, stacks of bumper plates, or small plyo boxes (generally the 12" ones work best), set up a course that athletes must slalom/step-up their way through. Wide slaloms really bring out the flexible nature of the hanging weights, and really put an emphasis on your core stability (be sure to scale the load accordingly--I recommend starting light and working up until you establish your personal "baseline"). Courses like this can be very dynamic and a lot of fun, and make for a great curve-ball event in CrossFit competitions, especially if paired with other stations like sandbag loading, lifts, sprints--sky's the limit!
If you kind of hate yourself, this is a thing. It was actually one of the main team events in WODfest 2014 (repeatedly, with various objects, including humans). It's...I don't know what to tell you, it's just plain hard.
Go inverted! Swap out some gymnastic rings with a set of Love Handles to do large-diameter rowing and pulling movements. Train with these, and that regular old pull-up bar should never be able to intimidate your grip again. Note, we don't recommend trying to kip or do muscle ups--your grip is deliberately being overtaxed; adding a bunch of kinetic energy to the mix is going to be a bad time.