The first thing you can improve on is the construction of buildings and hills in your layout. Make sure that your proportions of construction are right so that you dont end up with buildings that are too small to allow your train carriages to pass through. The simplest way to ensure that you have the sizes right is to use a run the train through a chicken frame before actually detailing it.Another tip is to make tunnels as dark as possible. Use black paint on the insides to lend it depth as well as some sense of mystery. Just picture how you feel when you actually go through the tunnel in a train. You should always work on the detailing of all your accessories. For example the cars and vehicles you use should match the period setting of your trains. If you have a scenic countryside location, having a modern day electric train pass through would make it look awkward. As a model railways hobbyist you know how irritating it can be to apply it to matt items. For a novice, the best thing to do would be to apply it to glossy items. The gloss actually allows you to position the decal in place sooner. And finally, the best thing you can do is join a neighborhood club of railways enthusiasts. This is the best way to get some tips that others have figured themselves and also to share the experience. Many a times, such clubs also form forums through which expertise as well as products can be shared. There is a lot that is discussed and shared at such clubs and you can meet all sorts of people from old timers in the line to those who have just started. Each one learns their own set of techniques on the job and you can benefit from this.