Oh goody, high output thread!
Don't worry about tyres. It took me ages to get them not looking like they came out of an early 3dFX Windows 95 game. For such a simple object they have a surprising amount of subtlety to them. Same with cars and bikes.
Alright I'll give this a punt. Everybody's going for their OCs so I'll be no different, but mine may pose a bit of a challenge, because Strop is a, um, ninja horse guy. It's easiest to think of him as a cartoon (funny) animal character, but that may not suit your style, so a description follows:
5'11" tall male with a slightly lighter-than-average humanoid build, but has a horse's head, a bristly, voluminous horse tail, and hooves instead of feet (quick reference). As far as horse attributes go he's modelled after a thoroughbred, with typical bay coat, black stockings and a white blaze starting from above his nose to the middle of his forehead. His mane looks like he just got out of bed (and maybe he brushed it into shape hastily), and both his mane and tail are black.
Now at this point I'll give you two choices: 1) ninja Strop 2) Doctor Strop.
Ninja Strop, as you can see, wears a tasteless one-piece coverall. It used to be more than one piece but as time went by now it somehow magically covers him from head to toe (save for an eyeslit, holes for his ears, a hole for his tail, and of course hands and hooves). Nobody knows how he goes to the toilet in that thing (not relevant), or how he procures items from it (cartoon physics). In a nod to the fashion lack-of-sense of Might Guy and his student Rock Lee, as well as the practice of taping the cannons of competition horses, Strop bandages his forearms and lower legs. His main tool of his trade is a longbow almost as tall as he is, and a quiver full of all kinds of weird and wonderful contraptions pretending to be arrows, for all kinds of purposes except actually piercing living targets (see an earlier version).
Doctor Strop, however, thankfully doesn't wear that one-piece at work. He's more of a dress pants, collared shirt, overly-colourful-tie +/- vest/jacket/coat depending on the weather. Here the tools of his trade are stethoscope and pen. He also wears spectacles.
Okay up to you, give it a shot.