Hi SaussageDog,
it would be helpful, if you show some images of the failed projects. It makes it way more easy to pinpoint the problems you are encountering.
Fixing distorted models could work if your work is in an area, such as cgi, gamedesign etc. where accuracy is not really an issue and the "correct" appearence to the viewer is more important.
For generating accurate models, one can say there is the principle "garbage in, garbage out". This means, if you do not follow certain guidelines regarding the data acquisition strategy, the type of model to be digitized etc. you will not be able to achive good models.
I'd recommend to read some articles about the basic principles of SfM, you even can find a bunch of links to pdfs on this side. Another recommendation is the vast archive of the ISPRS.
Cheers!