Rendering front of house

[Grantyy]

Hi any help or advice is greatly appreciated as I'm not sure how to mix or apply render.

I had a couple of Windows fitted almost 2 years ago and when he'd done he said the render needs replacing, I wasn't sure if he just meant around the windows or the front of the house in general, I guess the latter as there is a layer of flaking/bubbling around the bottom window and near the front door.
Do you buy render ready mixed or make it up yourself and if so how?
How do you apply render and achieve the speckled finish as in my images?
Does the render apply directly to the brick and is there any prep work needed?

Thanks

 

[vinn]

OP,
I know the idea of this site is for DIY'ers to have a go but you are out of your depth here.
There are now many modern renders or render and insulation but you need a renderer on site to view things. For instance, the reveal corners should have plastic angle beads.
There are lots of other variables, plus setting up & working off a scaffold is not for DIY'ers.

Your original render and Tyrolean is a v. poor job.