Some pointers from my side. Feel free to ignore.
1. Learn the art of self critiquing. Post only those which have passed your scrutiny.
2. Give up the urge to shoot anything and everything. Compose a mental picture first and then put it into the frame
3. Try to share something about the photos. Make your post interesting to people. "Comment Please" is a deal breaker for me.
4. Watch the background. Make sure it aids the main subject.
5. Photography=Painting with light. Make sure lighting is handled well in the photos. Use Flash, reflectors, Diffusers etc skillfully.
#1 I agree partly on this. Everybody posts his/her best photographs. Nobody likes to post photos which come out even half decent. I think one should also post the half decent pics as they will garner suggestions which will allow one to improve his/her work. Also photography being a subjective art it will differ immensely from person to person. It has occurred with me many times that the pics I liked, I felt something special were considered ordinary by others & vice-versa. So post pics even if they come out even half decent. This will help you in knowing where you felt short & even extend your boundaries while shooting the next time around.
#2 I agree completely on this. You won't get a perfect shot if you try to shoot everything around. Make a list in your mind about things you want to shoot. For e.g If you are thinking of visiting a sports-park, then you can concentrate on getting close ups of the players or try panning them. Offcourse you can click one or two shots like that of audience or the whole stadium but don't let your focus shift from the main subject.
#3 I agree. It is a good habit to include details like how & where the shot was taken. That's the reason I include details about the shot below the image. "Comment Please" sounds vague & if you happen to use it specify it. For e.g. Comment on the focus of this image or comment on the composition of this image.
#4 I partly agree here. You need to keep an eye on the background so that it doesn't spoils your subject. I have seen shots where the subject is lost in the background. I advise to get closer to the subject & fill the frame so that you get the very least of the background. In case you are shooting in a crowded location with lot of people, use manual focus & shoot at wider apertures to get good DOF differentiating subject & the extras. While panning try to get a clear background with as much few complexities as possible.
#5 Absolutely, Photography is all about using light to your advantage. Your photographs will come out good only when you shoot in conducive light conditions. Using strobes, reflectors, diffusers etc will definitely improve your shots but as said you will need skill in handling these equipments.
@all - I'll be writing a small book on photography this december. There I will discuss various photography, lightning, composition etc techniques in great depth. I'll need some pics for the same & it would be great of you if you could lend me some from your collections. It won't be for commercial sale & I'll upload the E-Book once it is done. Hope I have the co-operation from you guys!