Tents strategy
Every tree has one tent beside it, no two tents touch (even diagonally), and the numbers count the tents in each row and column. Use these steps, easiest first.
A tree with one square left
If a tree has only one free square beside it, its tent goes there.
Every tree needs a tent right next to it. Squares taken by other trees, off the board or ruled out can't hold it.
A line that must be filled
If a row or column needs as many tents as it has squares that can hold one, every one of those squares gets a tent.
There is no square to spare, so every square that could hold a tent must.
Squares a tent rules out
Once a tent is placed, the eight squares around it can't hold a tent.
Tents may not touch, even diagonally. Cross those squares off and look at the trees and lines again.