What works for me is:

Photinia Red Robin - needs loose soil, mine is too heavy so have really had to improve it. South/West/East facing. Makes a good hedge/wind break.

Hydrangea - my heavy soil seems to agree with it, keep it well watered but drained and it will be fine, mine is south facing almost full sun.

Azalea - I put a of of acidic compost and feed around them and they are in semi-sun under some trees and they have trebled in size in one year.

The hydrangea is sensitive to how acid the soil is. In acid soil the flowers will be blue and in alkaline soil they will be pink. This is the reason you sometimes see flowers that can't decide which colour to be - possibly a blue variety in alkaline soil or a pink variety in an acid one. If you have a blue variety that tends to be pinkish there is a compound you can buy to water into the soil.

As Sg says the colours of Hydrangea can be controlled, for blue flowers use sequestrene or aluminium sulphate, for pink flowers, use 2 ounces of ground limestone per square yard, use every year to keep these colours, Derek