Learn the midi controller and where everything is assigned. Learn it like you know your own schlong.
Assign effects over the master out on ableton and then assign them to keys on the keyboard. Ie assign the on off button to keys on the keyboard, so you can trigger crazy effects onj the fly, to the whole mix.
I try to produce everything as well as possible before banging it down to ableton for crisp and clean sound.
Pre sidechain your basslines if possible, before sampling them.
Set the levels in ableton so all the sounds hit the right level in the same place on the midi controller sliders, use the clip volume, it will make your life much easier, especially when you are using 8 or more audio channels. I set the correct volume to be about 7/8ths on the sliders on my controller, so I still have headroom to push each sound if I need to.
Have some fully made tracks you can mix in, DJ-Style, to give yourself a break, enjoy the crowd and vibe etc.
Don`t get messed up before hand.

try to use some live vsti. It makes things more fun and more live. I go for the less intensive but good workhorse vsti. Like Microtonic, Pro53, Audio Realism Bassline.

PEople will be more impressed when you start tweaking and the sound really changes, rather than just banging loops together.