Cass,

As the guys say Improv is cool, but followed with it is - 'if you can do it'... I am fairly new to this myself, although I threw myself in at the deep end. Did my 5th sarge session in Las Vegas and now take improv classes locally during an amateur dramatics club, which is actually really fun!

Personally, I wouldn't just go up to someone and throw them a compliment straight away, reason - if the conversation did go anywhere and you DHV then you've already given her 'a point' for just being there and complimenting her, think about how many times women here compliments and try something unique, two ideas for you on this;

Run up to a guy with some girls and use the one Style talks about...
"Hey man where did you get that top" "I used to have one just like it, but I gave it to a ex-girlfriend to borrow one night and guess what? After we split I never got it back, now I'm learning that I need two of every top I like"

(DHV showing pre-selection, under the radar approaching the guy in the group)

If you can be cocky funny with it, try a backhanded compliment...
"those shoes are a bit... but I really like that top" or "is your hair real? well it's nice anyway" (most likely to use this on a girl who is hot and knows it to bring them down a few pegs)

If your day-gamining try this, go into a coffee shop and throw the "what's good to eat/drink here?" to either customer or staff, although customer works better whos waiting in line, thats the opener and then just work from there...

Open with: "whats good here" (customer or staff)
Root with: "always walked past this place but never been in"
Time Constraint with "I can't stay long because got an appointment to get to but..." (get the coffee in a take out cup)

or ask a staff member "what could you recommend?" and then go for something different (thats was someones material from, Mystery's lounge I think and it gives you a subtle joke with her).

Fluff for a bit...

Run a piece to get a hook possibly "caffine stimulates the brain but can make it more receptive" then go into a ESP or Cube type effect,
Finalise with a DHV a bit more fluffing and a # close.

------

Again I appreciate some guys on the forum don't like canned material but I don't have a great deal of knowledge about your current experience, and I think I was the same a few months ago. Key is take baby steps to get a feel for material however, sometimes it is worth just flying in at the deep end crashing and burning and then evaluating where it went wrong.

If you are starting out you can just approach a group ask a question or opinion opener, remember to give the false time constraint and root it then when you get the answer if you don't feel comfortable or cant think what to say, follow up with your eject "pleasure meeting you" and walk off, nothing lost but something gained - you opened!

Good luck with it buddy
Ambitious