Layouts and layout building

Hi,
I am trying to decide how to design my streets and sidewalks. Does anybody have any tips/pics of a good process of modeling sidewalks? I would like to use the Woodland Scenics products.
I have noticed in a lot of layouts that the buildings look like they "sit" higher up then the ground/curb How is that done too?

Thanks
Art

Well, in 2 previous "layouts" (more like modules) I have used Durham water putty (in styrene forms, kinda like real concrete pouring) w/ some grey water-based paint to give a 'concrete' look (wasn't my best effort, but if the idea is that you then paint the grey colored sidewalk whatever concrete color, and if it chips or scratches then it looks less conspicous than the bright white that chip would otherwise be) - then I used styrene air-brushed concrete color (I kinda used Floquil Concrete & Age Concrete mixed, then a lite overcoat of thinned black - many different concrete formulas out there, keep your finished layout lighting in mind as what looks good under, say regular flourescents may look sickly under incandescent and vice-versa).
You can build 'bases' for your buildings, say using .04 styrene sheet under the building footprint, surrounded by .06 styrene sidewalk strip, so that the building sits higher than the road, but is still 'embedded' in the sidewalk.  You can account for driveways and alleys by having no base at that point, run the road right against the building - lots of ways to work and experiment w/ this for reaslistic effects.  Foam core as works as a base, not too convinced that thin wood sheet is a good idea.

I used double-sided foam tape about 9/16" wide.  It could stand to be more accurate in terms of scale height, but it turned out well. Carving curved sides at intersections and then painting the whole with a blend of paint and plaster of paris resulted in a believable look for me.

Thanks, do you have any pics you could share?

Mine are made from plain sheet styrene.  I cut the back edge to the same shape as the structure behind it, so that the building sits down inside the sidewalk.  For an urban setting, this gives the impression that the concrete was poured right up to the building.  It also prevents light from leaking out the bottom if you illuminate the structure.

I just painted the styrene shape light gray, and added sidewalk lines with a #2 pencil.

Sure, here is an image that shows the tape compared to the styrene kit base for the popular brick store model to the right. 

what Scale is this HO or N

Mine is N

Are those evergreen sidewalks?