Well the single tutorial for things seemed to be the winner so far so here is part 1 of many many many little background tips and tutorials from me.
All of the trees were created on Photoshop using normal brushes on round. The leaves can be found in these brushes packs: fav.me/d4mwyh6 - I use these ones the most they are fantastic! fav.me/d24laop - Didn't use these on this occasion but they are also great!
Top tip for leaves So that you don't over power your tree with leaves you should lower the flow of your brush setting at the top of Photoshop
If you have any questions shout up! I shall do my best to answer them.
Hells yeah I use ref's for trees! Well...if I wanted to draw them properly I would, say I I wanted to draw a certain type like cherry blossom or silver birch, but normally I just make them up like tree number one and then add leaves