I recently discovered this pond, however as you can see by the picture, it has lot of underwater vegetation.  My soft plastics kept getting caught up.  And I didn't see any top water action. What techniques/lures should I try?

I'd try maybe a spinnerbait worked high in the water column.

Then I'd try some weightless plastics. Especially a Zoom Finesse or Trick worm. These have a slow sink rate and you can actually work them pretty close to the surface. Also weightless plastics seem to not grab vegetation as easily a weighted.

Hope this helps.

Along with the trick and finesse worms, try a floating worm.  

Fishing similar conditions I have been having some GREAT luck with the GYCB Kreature on a 4/0 EWG Gamakatsu Offset Worm Hook, weightless and weedless. I fish it like a spinnerbait with a steady retrieve and an occasional twitch. Using this presentation, you are fishing the lure near the surface and it will not hang-up. You're still going to get a little gunk now and then, but I think you'll be just fine.

I will second the weightless soft plastic option.  A Sluggo or Zoom Jerkbait would be my first choice, but I would also try a soft plastic frog (Cane Toad or Sizmic Toad) fished under the surface - I catch more fish on my toads by letting them sink rather than buzzing them.

I would fish this area with a top water lure, a floating plastic worm, and a spinner bait with a colorado blade using the wake retrieve.  You might also try some weightless plastic frogs with weed guards on them.  Cast it out, and after you feel the resistance of the vegetation start with a pull and reel retrieve.  Also, I would use a 30lb. braid like Spiderwire with a 18" to 2 ft. leader of 12 to 17 pound mono or fluorocarbon line.   I like to use a #5 barrel swivel when I use braid because of the tendency of the plastics to twist.  

Then again, with vegetation that thick you might be able to get away with tieing on straight to the braid since the vegetation could mask the line, and you'd have a better feel for and control of the bait.  

One that I like to use is Berkley Powerbait Realistix.  Here is a link.   http://www.berkley-fishing.com/prod.php?k=74926&sk=74917&p=PURSCKF4-AL  My local bait shop keeps these in stock for me since I go through them like hot cakes.  I bet that I've bought 15 packs of them since they came out.  Bass love 'em, but they only have about a medium durability because of what the frog is made of.  I'll trade durability for catching fish all day long!  

I think everything has pretty well been mentione here. However, I would go with topwater, light softplastics (like a floating worm) or use a spinner bait and just retrieve it shallow...