Nearly as soon as I started out in Ngauge I wanted a scenic background behind my layout.
I started by making a 3 legged double sided board 8"x 60" that slotted into 3 soclets built to the layouts back famework.
On one side I went for Pecos 'mountain lake' mingled with bits of 'country with river' and on the other  'village'. Within weeks I was shocked by the reults of 'village' because it was so horribly off scale for the position I was using it in.
Recently I even noticed the cottage near the river on the other side is in the middle distance but far larger tan some of my houses etc. in the front of the layout.
Theres so many more choices these days at resonable prices I must set to and get ome that are more in keeping with the size. Ive noticed whist browsing forums/layouts on the net and in magazines that many othrs have fallen foul of the perspective mistakes.
Do you plan your backgrounds to the same degree as the layout and have you ever made  mistakes like I have?

I plan to use basic backscenes where there are no buildings or where there are buildings they are extremely small and in the distance

If you take this one as an example, once aligned to the backboard the perspective should be more correct
http://www.woodhurst.webspace.virginmedia.com/img/08834-large.jpg

I certainly did put a lot of thought and research into my backscene as I think it's a very important part to get right - like a picture frame needs to be right for a picture.  I don't think I made a mistake yet.  I bought a photographic backscene off eBay that is just right for my location.  No buildings except in the distance.  I dont't think it's been on eBay for a long while now.  I keep trying to find it because I wanted to post about it if it's still available.  I have since bought Gaugemaster backscenes and some from International Models: http://www.internationalmodels.net/acatalog/9_Inch__9___Backscenes.html.

I have cut out the house sections away from the sky etc to mount as a layer between the backscene and the low relief houses.  I also mounted a lot of buildings from texture sites and the internet.

Take a look at my website backscene section:

http://www.marksmodelrailway.com/Marks_Model_Railway/My_Albums/Pages/Backscene.html

You certainly look as if youve got it right MM.
Theres a whole range of backdrops available now which I never knew about when I started off.
I realy must look into replacing mine preferably without houses/shops etc on them