I agree with everything said in the past six posts. The mentality that you have to accept where you are now, and wish to better your skills, is definitely a start. Now, where to go from there? You could do either of the following:
- Definitely ask opponents why they think you lost. You can still learn from your victories, but like the old cliche, you learn more by losing than by winning. With that in mind, when you lose a game, ask opponents of their thoughts. Ask them what they would have done, and more importantly, why they would have done it.
- Ladder settings will help slightly. If you want to get better, I say practice playing effectively on all maps, templates, settings, etc. Players who can analyze a map for the first time, and still pick reasonably well, are much more skillful in my opinion than someone who specializes only on one setting. Sure, you can get good at one or two specific templates, but it's not going to guarantee you get better that much. Ladders will prove to other people of your skill, but they don't measure it that well. Anyone with the motivation can get good at Strategic 1v1 and get First if they really tried, but that doesn't necessarily mean that they're good. Therefore, try all types of games, it'll build a better sense of analysis and strategical thinking.
- Get a tutor. Tutors are helpful, because they'll be able to play you and accurately tell you your strengths and weaknesses. Even if it's just a player that you play with every once in a while, who you trust to give good criticism and sound advice, you'll learn a lot from them.
- Play practice games with higher skilled opponents. Make games with high pre-requisites. It will ensure that you get good opponents to practice with. Teaching will only get you so far; you need to practice yourself and put your learned knowledge to good use to get better.
A lot of this has been said already. There's not really much I can add that has already been mentioned. I know that when WGL was around, it helped to criticize game-play effectively, and I was able to learn a lot from other perspectives. But, you can still find alternatives. And if WGL ever comes back on, then you should do just that. Play the tournaments, and listen to the stream to games that you might have won or lost. Listen to games between "top tier" players. Check out high-ranked players' games on the ladders (if you're trying to achieve ladder recognition) or ask them personally to give you insight on their playing style.
^ (Did you see that? I'm actually paying attention to aesthetically pleasing forum posts!)
Now, on the subject of clans. They can help you a lot, if you know which ones are capable and willing to teach you. You don't really have to be in a clan to learn effectively, but the community that clans bring certainly will help. I know there are some clans that will help you grow as a competitive and skilled player, it just comes down to whether they accept you or not. I would invite you into [V.I.W], but we're not terribly competitive or anything. Not sure if that's what you're seeking, but I'm sure if you wanted to, we could accommodate you into our clan for some time. Either way, I hope you find what you're looking for.
Best of Luck,
-AWESOMEGUY