New here. Advice on robin/ wren nest box

Hi, 

any advice on where to put an open fronted nest box for a robin or wren in our garden?

I rest that both species will nest in the same type of box. In terms of the location is it different for each species? I saw on a Simon King video on YouTube that you can place many of these types of bird boxes in your garden quite close to each other. He said in the video that he has had a Ren and a Robin nest virtually next door to each other.

at the moment I have two boxes nestled hidden in Ivy that’s quite close to the garden gate so probably not private enough for a robin ? I read this morning that Robins only like private areas? What about wrens.?

Am I too late in the riding season to move the nest boxes or put a new box in a more private space?

any advice would be gratefully received

thanks, Scott