Hand-Mixing: I don't typically use a blender for guacamole, preferring a chunky texture where all the ingredients get to shine. If you do use a blender just pulse gently until you get to desired consistency.
Lemon or Lime: classic guacamole is made with lime juice and that works perfectly here as well; lately I've been using sweet basil more and more in our guac sometimes with cilantro sometimes without - fresh and abundant right now and makes a nice change - and like the combination with lemon.
Adding Heat: poblano and jalapeno pepper would be my top choices; my friend Traci has a tutorial for yummy charred Jalapeno pepper
here.
Thai Basil: I had the idea of making a Thai basil guacamole with bird's eye chili (Thai chili) I was so excited about the combo but ultimately didn't like the taste; it just didn't work imo.
Make-Ahead: guacamole is truly best enjoyed shortly after assembly. The citrus will help support the color of the guac for an hour or two (it delays oxidation/darkening) but beyond that, you'll start to lose some of the fresh taste (happily it only takes a few minutes to pull together).
Service: not just with corn chips and veg, we've been enjoying this guacamole by the heaping spoonful over all of our proteins! Pretty much goes with everything.