Tone matching is for emulating a specific tone/sound... for instance you would make a lead sound that resembles Steve Vai's lead tone, then use the tone match to analyse a few seconds of just Steve Vai's guitar sound (no other instruments) from an audio track, then match the two tones together.
To make a tone that works well in the mix, the best idea is just to keep tweaking the amp settings, maybe add a eq block before or after the amp and filter out some of the very low and very high frequencies, whilst boosting some mid or high frequencies, a bit of reverb and a bit of delay, and you should be sitting in there nicely.
Reverb and delay both create the illusion of the sound being further away, which is good for setting in nicely in a mix, but sometimes you want a sound that really stands out and is very in your face upfront, it all comes down to taste and what sort of effect you are going for.
