Agreed. Give this a read for a pretty complete summary of them:
http://community.boredofstudies.org/4/english/338471/complete-visual-technique-list.html
Techniques are just ways of describing how we use language. Every sentence has techniques. If you don't include them, you're missing a big part of the analysis.
Pick a genre first, then go from there. Comedy? Drama? Slapstick? Biography? What interests you?
From there, look up the major playwrights of that genre, and read. Most good libraries have copies of the plays. Either find or adapt a section of the text that speaks to you.