Cabooses can be unique between railroads, even more so than engines.  One of the reasons is because alot of railroads built their own, or had them built to their specific needs by outside car builders.  Like engines, there were different cabooses for different jobs, either different sizes or designs, or simply outfitted differently.
I will simply upgrade and detail commercially available caboose models like those pictured above for the fictitious Blue Creek railroad.  For the Clinchfield, Southern, and C&O railroads, I will detail commercially available models that fit for now.  Down the line, some of the more unique cabooses might be candidates for scratchbuilding, but anyone who has looked through the rest of this website will understand that there are several projects ahead of any caboose scratchbuilding project.
Once the roofwalks were glued into place, I removed the thick end rails and ladders from the frame.  I added an end piece out of styrene, built a brake wheel stand out of .010" styrene, added an MT brake wheel, bent an uncoupling lever from .008" wire, and simple end rails out of .010" wire.
 
Once that was in place, scratchbuilt a ladder with curved upper rungs out of .008" wire.  At first, my gap-filling ACC was too thick, and "gobbed" up on where I glued the rungs to the ladder.  So I removed them, shaved off the ACC, and used a thinner ACC for those pieces.  I drilled the roofwalks, and then mounted them.  Once I made sure that it worked, I did the same on the other end.
 
I painted the caboose body with ATSF red, the frame, ends, and roofs with engine black, and some of the grab irons with reefer white.  I added MT trucks with medium extension couplers and the restraining springs, and the caboose was ready to run.
 
I will letter it for Blue Creek RR in the future, at which time I will paint it with Dullcote, and then affix glazing.  This will wait, as I still have to decide on how I want the Blue Creek RR lettering to look, and decide if I want to print my own, or get some custom made. 
 
I had a cheap Model Power steel offset caboose, so I decided to try out a few details on it first, because it wouldn't be a big loss if something didn't work out well.
 
First, I replaced the steel weight with non-magnetic weight.  Then I shaved off the grab irons, drilled the appropriate holes, and installed .008" wire grab irons.  I used varying sizes of screwdriver handles for the curved grab irons, and screwdriver shafts for the curved portions of the other grab irons.  After they were glued on, I painted the inside of the caboose black.  As you can see in the Union Pacific caboose above, a yellow plastic interior would stick out against the planned red.  Then I added a detailed smokestack, and used .006" wire for supports.
 
The roofwalks on this caboose stuck out as much as on the Union Pacific caboose.  I carefully removed the roofwalks, cut down the roofwalk supports to a more realistic height, and shaved the post supports from the roof altogether.  I filled in the holes over the end walkways, but I didn't bother with the others, as they wouldn't be visible when the roofwalk was replaced.  For the roofwalks themselves, I flipped them upside down, cut off the mounting posts, and sanded the roofwalks down to a more believable thickness.
Even though the cabooses pictured above will require a bit of work, Atlas produces some nice extended vision and regular cupola cabooses, and one is even available in one of Chessie's colorful safety schemes, as seen to the right.
 
A few more of these cabooses will be used for other C&O and Clinchfield cabooses.