I tend to use more body movement to avoid their strikes and as they start to bring it back I blast. I don't use destructions all that much, a litte bit but normally when I block I use a variation on the crazy monkey blocking system. Another thing Ido is, imgine opening your hands in front of you at face level, thumbs touching ad extending forward a bit (sort f like the Spear). I use that against most jabs and straight rights/lefts.
I do include a lot of fast, low front and thigh kicks to set up the blast as well. Fo example if they use a straight right I'll maybe deflect with that Spear thing (with a slight side step usually), shift to my back foot and thow a low front kick and blast off tht.
I don't really seek out destructions, but if they happen than great. They work fine if you connect but that canbe tough to pull off.
My thigh kick is usually with my front leg unless I'm trying to actually hurt their thigh. If I blast off a kick the kick is mostly a distraction. I use a lot of different things for my entries I see no reason to just go for destructions honestly.

I believe the cornerstone of JKD is the ability to intercept. That is what many of the top JKD instructors explained to me when I interviewed them. You can check out some of the interviews I've done with top JKD instructors at http://www.JKDnewsletter.com