I know this is an oldish thread, but thought I'd give it a bump!
Personally, I love bloom and wild. I got sent the loveliest bunch just after my baby was born! 
They have the option of either letterbox flowers, which come in little nets and need arranging, or some that come with a courier and are prearranged in a bunch that just gets popped in a vase.
The letterbox ones are my favourite personally - they're not too tricky to arrange, you get a good amount for your money (especially if you use a discount code), and I've always found people love the novelty value of it.
They have a really good referral scheme, so thought I'd share mine - you get £10 off, and I get credit added to my account 
Once you've registered, they then give you your own referral code to go on and share with others, so you can start earning your own credit too!
Here is my active £10 off code - they've got some gorgeous peonies at the moment!
refer.bloomandwild.com/m/ode/sk3nx-8a6b274908