What are some of the defenses lawyers use to get someone out of shoplifting charges or to be not convicted?

Basically just first offense and ability to do restitution, possibly without clogging up the court's time by spending more than 30 seconds on it. It's kind of assembly line justice, not something you see on TV. No time for statements of good character or reasons someone might have made a little mistake.

That depends on the nature of the evidence against you. If the store caught you outside the store with unpaid merchandise, there is little you can do.

Yes, they will have to prove you did not do it, that the DA can not prove the elements of the crime. Show an error in evidence perhaps.

So what is evidence ? Did they catch you with goods in hand?