The first thing I do is check my signal in the shack receiver, but lots of times I'm overloading my receiver and I sound like that buzz saw. Is this really what others are hearing? Maybe being so close makes a minor problem sound worse than it is.
The next step is to have a friend a few miles away listen to you and, possibly, hold a phone up to the speaker so that you can hear your self. This can be real helpful but lots of times I need a more complete listen.
As a final check I recommend taking advantage of one of the many web based radios available all over the world. Link into one of these, turn on your own computer speaker, set the frequency/mode you wish to test and then transmit. Given needed propagation you can listen to yourself and the waterfall display helps you see what your signal is actually doing.