compare them to the symbols in the on-line dictionaries

first, you need to notice, even if you can't write or read Chinese character, you could absolutely speak it very well. that's for sure, trust me. i see many people who speak chinese frequently but can't read on simple message. now, come to your question, how to make sure you write right? i think one easy way is to type this character on your computer or cell phone. then you can check your own writing to see if it is right.

Well, there's a couple things I can say. If you find an online dictionary they often have the stroke order and how to write each stroke (line). Whether you care about the order of the strokes depends on you, but some people care. But you should be careful because there are a lot of similar looking characters which are written differently (入 vs 人，干 vs 千 etc...), and the relative size of various strokes does matter. I do use skritter, but a word of caution. Skritter isn't precise enough to pick up little details, so it only train you in the broad brush strokes, and won't teach you to write super small like you need to with say 赢 .

we can work together.

That's a good question. I still haven't learnt to hand-write any characters, and would be interested in what you find. I have been concentrating on writing them. These days, there is perhaps little need to hand-write, as long as you have a smartphone with you. If you did want to hand-write, I guess if you had a language partner, you could scan what you have written, send it to them. and they could read it and check it for you.