This is what i have done to my bike in order, from more useful to least useful:
Make sure you set your Rear sag properly, You would not believe the difference it makes in handling! (i weight 176lbs and setting 5 gives me 28mm)
Change your fork oil to 10W, it really helps with the nose dive, i still have to set the front sag with washer, will do it soon. Some people go as high as 15w or 20w, 10w workes for me.
-1 front sprocket and speedohealer, it really wakes the bike up but definitely becomes a lot buzzyer. If you don't like cruising at 8000 rpm plus don't do it.
The bike is fine with it though, i rode a 300 Km trip keeping rpm between 8000 and 13000 rpm and the bike didn't overheat or seem to care even after 2 hours.
Foot pegs, IMO the stock foot pegs are very slippery and i feel like i have a lot more control with aluminium pegs.
FZ1 bar and Progrips grips. Gives you a more aggressive riding position and is easier on the wrists. Makes the bike feel more flickeable!
The Progrips (717) are so much nicer than stock, you barely have to hold on to feel in control, feels a lot safer to me.
Leo Vince Exhaust, just cause it sounds good...
Change the bulbs to better ones, you can get a lot more brightness from the headlights and the brake lights with good bulbs!
Sliders all around, i have frame, axle and swing arm sliders, maybe a bit overkill, but they look cool, and every little helps.
New mirrors, IMO the original ones are ugly and i couldn't see anything else than my elbows in them!
Radiator grill, when you know the price of a radiator, and see the crappy stock grill protecting it, it just makes sens.
Seat cowl, purely for looks, but it does look good!
Belly pan, no real function other than look cool...
Tail tidy, as the name implies, it cleans up the rear nicely, but will not protect you from water projections as well as the stock horror.
Smoked lenses on the turn signals, just cause they look badass!
Paint the radiator cap mat black, once again, just for looks, but i really hated the bright orange cap!
I am also in Belgium so if you need help finding websites that sell all those goodies let me know!
Here are a couple pics, threads are better with pics!
Those were before the FZ1 bar swap and the footpegs:
