|Mike Cougill's excellent book, Detailing Track. OST Publications.|
One thing you run into with the attainable layouts that I advocate is that they are...well....they're attainable. Sooner rather than later you'll have them up and running. I'm seeing abundant proof of that from the photos I receive on a weekly basis. Once you do have a layout that runs reliably, the next step is to pick small sections that catch your fancy and upgrade them, and your modeling skills at the same time. One avenue you can go down, and one I find relaxing is detailing your track. I'm assuming that most of you are using Walthers, Peco, or Atlas flex track to start.
I don't advocate removing massive sections of existing rail at a time. What I do suggest is pulling up eighteen inches or so of tangent track somewhere, perhaps at the end of a spur, and play around with super detailing. Abandoned rail is a common (and seldom modeled) aspect of the rail scene. Super detailing a weed choked section of abandoned rail would be another safe option to get you started.
An excellent resource to give you ideas and help you on your way with your foray into detailing track is my friend Mike Cougill's book, Detailing Track. This is one of several excellent volumes in his Masterclass Modeling Series. Not only does the book go into depth as to the 'how to' aspect, it also delves deeply into color and texture. There are numerous close up shots of the prototype to guide you. It's just a fantastic resource from cover to cover.
In terms of sources for detailed parts you have Proto 87 Stores, Details West, and Detail Associates to name a few. You don't have to be modeling to Proto 87 standards to make good use of the Proto87 stores inventory. I go through the Details West rail bars (part number RB 933) at a rapid pace. Micro Engineering makes some nice wood ties.
If you do go the super detail route you do need to change one thing up and that relates to rail color. When using flex track with oversize details, such as Atlas, I advocate painting the rail a dark color to hide its deficiencies. If you do that with super detailed track you won't be able to see your work. For detailed track I suggest a lighter color such as Floquil Rail Brown.
On my own layout I don't bring all of the track up to the super detail standards but pick and choose sections here and there. To be honest with you, in HO the finer details aren't always that noticeable. I just do it because I find super detailing track to be very relaxing. You may too. Give it a try.