12 Ways to Help Keep it Manageable

I've seen many layouts come and go over the years.  The answers are different for everyone, but I hope the following might save someone a disappointment or two.
 1. Realistically assess your resources and limitations BEFORE you commit! - This means EVERYTHING: spare time, spare money, your current skill level, your desire, physical limitations (both space-wise and your BODY!), your current lifestyle, stability, even your friends, neighbors, and most importantly your immediate family - including pets.
 
2. Prioritize and separate your 'needs' from your 'wants' - Unlike Barbie, you usually CAN'T have everything.... Set a minimum acceptable standard that fits with #1 and start there. You can always add more later. The bigger and more intricate, the more interest (sometimes), and the more work (always).
 
3. Don't be afraid to ask questions, then actually listen to the answer -  Even if it sounds simple and obvious, make sure you really understood it. The only 'dumb' question is the one you learned the answer to the hard/expensive way because you were too proud to ask.
 
4. Don't be afraid to start over - Before you can run a marathon, you have to be able to walk that far. EVERYBODY stumbles. EVERYBODY tries something that doesn't quite work out as planned. EVERY layout has had at least a FEW revisions. Yours might turn out to be the exception, but it probably won't.
 
 5.Practice patience - Just because it's overused and trite sounding doesn't make it less true; Rome WASN'T built in a day.... or even a week. Some stuff just takes time. Instant gratification is a Madison Avenue myth. Besides, if it WAS fast and easy, you probably wouldn't really appreciate it anyway.
 
6, Make a budget and stick to it - The easiest way to get yourself into trouble is to over commit, be it money or time.
 
7. Address little problems as they crop up -  Stuff rarely improves by itself. It usually just gets worse, and even if it doesn't, something else usually goes wrong, too. Sounds depressing? Depressing is avoiding something that used to be fun because you let those little things get out of control like a snowball rolling downhill.
 
8. Ask for help - At some point everyone needs it. Some of us are blessed with a significant other that enjoys getting dirty and sweaty. Others have friends that they can rope into helping. Or, if you're really stuck, hire a pro....
 
9.Measure twice, cut once - Not just physically. Take time to think things all the way through before you decide to do something...
OTOH
 
10. Git 'r Done -  Don't spend ALL your time thinking, or you're just daydreaming. Get out the shovel or hammer and go lay some track!

11. Don't set project deadlines - Instead, set how many HOURS that you intend to work that day... Then you won't feel as much like a failure if things don't go quite as planned
 
12. Plan how you will access every single foot of track. - I can almost guarantee that if it's hard to get to, that's where you'll have the most trouble. There's not much more upsetting damaging your new locomotive because you had to fish it out of a tunnel with a broom handle.
 
There is the best help I can offer for layouts and for life, without any mumbo jumbo, or sugar coating. How you use it (or not) is up to you.

Know your target audience

Folks always seem to like to argue over proper 'scale models' versus semi-scale or 'toys'. I'll clue you in on a secret.  Everyone is right, and everyone is wrong. It all depends on the frame of reference and who you're talking to. Like it or not, LGB was THE gold standard in large scale trains for decades. They carefully chose their target audience - folks who wanted robust, good running, good looking trains for indoor and outdoor use.- And were willing to pay for superior quality. - They produced exactly what those folks wanted. If you preferred perfect scale, or cheap and cheerful, they never claimed to be what you sought. Yet some folks slammed them for not being so. Bachmann and Aristo-Craft OTOH have chosen to cater to those who seem to prefer lower price and a more scale appearance over quality and durability. As with LGB, it's not wrong, just a different target audience.
 
So, what has all this to do with you and me? We need to take the same approach. When we plan projects, we need to decide WHO our target audience will be. If you are building for a club or other train folks, you will need a different mindset and standard of finish than if you're building for family and friends. Trust me, your kids won't disown you if something is off by 3 scale inches or even a couple scale feet. MOST of your train buddies won't actually embarrass you over it either (unless you REALLY make a hash of it.... but then, those that do probably deserve to be shown the door anyway.)  While a Colorado NG enthusiast might be really impressed if you build a historically accurate model of D&RGW #483 as she appeared on the afternoon of August 26, 1943 at 3:52PM.... your 4 YO grandson will just be mad because you say he can't touch it.
 
If you want to mostly run in public, then you should plan for durable, easy to repair, and reasonably good looking. Most folks can't tell a Baldwin from an Alco or Aster from New Bright, and really don't much care, either.  Kids (and many adults) WILL try to touch your stuff - So i is much easier to plan for thatt than to get upset afterwards. Thomas WILL get more attention than your scale models. Most folks will just ask how much it cost because they are curious, or maybe because they think you're a bit daft. - not about why you put an incorrect paint scheme on something "XRR never owned".  There may be a few, but most won't give you grief, even if they notice.
 
If you want to win a model contest, get printed up in a magazine or are building for a museum, then by all means go whole hog. Put a perfect scale pickle chip on a perfect scale sandwich in a perfect scale lunchbox in that perfect scale toolbox. If you just plan to sit it in a case to look at, then you probably may want to draw a line someplace short of that. If you plan to actually RUN it - especially outside, then please realize that some of those more fiddly detail bits are probably not going to hold up for very long. And once lost they can be a bear to find!
 
Generally, for most of us,  if all the parts look like they belong together, and the model works visually with everything else on your layout, then it IS 'right', even if it is wrong. When you take in the whole picture, you won't really notice that the gauge is off by 6" or the building has 4 windows instead of 5. And stuff that looked like total crap from 3" with a flash often will look great from 3 feet away under natural light. OTOH a perfect scale model that overwhelms everything else around it may totally ruin the mood you are trying to set. Okay, so painting an undersized cow to look like a pig might not be very convincing when viewed up close, but I hope you understand what I'm trying to say.

A point to remember is your layout is (hopefully) a sort of picture, or series of pictures, that tells a story, and YOU are the artist - whimsey, selective compression (aka the rubber ruler), impression rather than fidelity, even rigidly counting rivets ALL have their place in your properly equipped toolbox. Knowing when and how to use them is what separates the fantastic from the merely good. It IS an art, not a science, but it can be learned. And carefully choosing your audience (even if it is yourself) and playing towards what they want and expect is the first step.