I bought my bike this last summer and during the down season I am modifying my Honda CBR600F4i to my taste. Some of the mods are purely cosmetic and some are functional. All of or almost all of the performance mods have already been done. I also had to fix a modification done by a previous owner, which hooked both head lights the the high beam switch. I didn't like the all or nothing approach to the head lights and took it back to how it was supposed to be stock. This is not so much of a step-by-step as an overview to what I had done, Notes, etc. made on the way.
* Undo the previous owner's all or nothing headlight mod, back to stock.
* replace all the lighting, except the headlights, with LED lights.
* Add an external watertight/ waterproof cigarette lighter socket (on a switch and fuse) close to the gauge cluster/ handle bar area (for gps, etc.).
* Add an internal mounted cigarette lighter socket in the trunk, under passenger seat (charge phone, etc.).
* Add Body lights (on a fuse and switch).
I store my bike at a friend's house, whom is generous enough to let me store and work on my bike in his heated garage. So I spend about 2 days a month (kid free weekends) working on the bike (mods I am making and general winter maintenance).