Hoople is absolutely correct. We have little background info to know where to start, such as how many total miles, miles on front and rear tires, driven mostly on smooth roads or rough county/country roads, stored inside or outside.
Almost anything that moves could contribute to your problem. Front or rear wheel bearings, cupped tires, wheel balance, health of fork bushings, swing arm bushings, engine links, and perhaps things I haven't thought of. How deep are your pockets,a nd do you want to cure the symptoms or dig for underlying cause?
Mine had low mileage, sane driving, and inside storage going for it so I checked more for adjustments than for worn parts.
There are a few things you can do for free or for not much shop time. A shade tree check for front wheel balance can be made by removing the calipers and spin the front wheel slowly by hand. Without the brake drag, it will spin quite freely and if the same part of the wheel always stops on the bottom, you have a balance problem. If it stops randomly, balance is OK, not as good as it would be if optimized on a real balancer, but you can at least see if you need to take the wheel to someone or buy your own balance gadget. Next if you tighten the steering head to the tight side of the tolerance, that wouldn't hurt.
If your front tire is approaching needed replacement, perhaps now is the time to eliminate irregularly worn tire as contributing to the problem.
By having someone hold the front brakes, or use a bungee cord or the like, you can push and pull on the front wheel to check for play in the fork bushings and perhaps find any looseness in the wheel bearings. Having someone hold the steering firmly against one stop, pushing the wheel from one side, then the other might also show wheel bearing or fork bushing problems.
If you have a level which indicates inclines, you can check vertical alignment of the engine swing arm with the frame by centering the steering and measuring and comparing the angle of the front and rear brake disks. Two long straight edges laid against the tires from back to front will check chassis alignment. After this point, I'd have to take mine to the shop.
Good luck, hope you can get satisfactory performance before you can no longer afford to buy gas for it. The details of most of what I have mentioned here are contained in the appropriate shop manual, it would be a good investment.