If you would like to place Photos/Posters/ Hang Flowers or Fairy Lights, Flowers etc to walls we recommend you use 3 M Command Strips /Hooks.

To attach or hang them to the shell there is some advice here on how to use these. 

Please use the ones that are capable of holding the weight of the item you wish to attach and please be careful when removing them from the wall.

You can get these from B & Q, Amazon and other good retailers.