I'm going to look at what appears to be your most recent set, Cosplayers on Ice. I'll describe the photos as best I can based on names tagged in the photos.
Overall pretty good. Nice and sharp, focus hits the eyes just about every time, which is absolutely vital in portraiture. White balance looks pretty good. Lots of close-ups of faces, which I like to see.
I think you can stand to cull a little bit more. If you have two or three that are very similar, cull all but the one BEST ONE. For instance, let's consider the three with Amy and Shannon, wearing the Naruto headbands. They're making the same exact pose and facial expression in all three. I would probably keep only the middle one, as it has the least amount of distracting stuff in the background. If you want more than one, make sure the second one is different: Full-length, or a different pose/face, or drastically different lighting/background.
Nitpick and pet peeve: I'm personally not a big fan of photos that are tilted without good reason. Some people call it the "Dutch Tilt" but I call it sloppy
You can use a tilted framing to add some discomfort and drama to an already interesting photo, but you can't turn a boring photo into a dramatic one just by tilting the camera. Opinion: Keep your horizons level and/or your verticals vertical unless you have a very specific reason to do otherwise.
I would have liked to see a more varied mix of both close-up faces and full-length portraits. Face close-ups are great, don't get me wrong - but especially with cosplay, the whole costume is important down to the bottom of the boots or shoes. Out of the whole set, the only ones where I see the shoes are the ones of Alley posing on the ground. (and the action shots of ice skaters, but those don't count)
In portraiture, spend as much energy looking at the background as you do looking at the subject. Frame the subject with pleasing background elements, and move your feet (or move the subject) to obscure unpleasant background elements. Sometimes this is easy, sometimes it's not - but at a minimum, I don't want to see a port-a-potty in the background
Overall not bad. Keep it up, practice practice.