I find that if you go at it without having a break. Even when a model is going well you can get bogged down and that's when mistakes happen. I find that doing a couple of hours a week is an enjoyable balance. When I complete a stage on my model and it goes how I like it to I think oh I'll just start this bit now...that's when I stop myself and come back to it ready for some more enjoyable time on the model another time.
My revel golf was completed quite aggressively, I spent sometimes 5 or 6 hours in a row doing the model and found that I enjoyed it less when more than 2 hours on the bench. I got grumpy from the late nights too.
Then when I started my nissan le man car, even though it didn't turn out as good as the golf I actually enjoyed it more because I limited my time on it at any one go.
Now with the 300sl I am thoroughly enjoying the model as I'm not rushing to get it finished, yes I've made mistakes on it, but I have taken each stage in my own time and the mistakes I have rectified I have enjoyed doing that too.
For example I mucked up the wheels a week ago, did it annoy me? Yes a little. I then thought I'd start white priming the body shell and halfway through my
airbrush broke so now I have to order new
airbrush parts and more model parts to replace the melted wheel. I made the body good what I could with my cheap backup
airbrush and since last week I haven't even looked at the model. Now I'm probably not going to get any time on the model until end of month but as each day goes by I look forward to it more. If I was going at it every day or for hours at a time I'd be temped to finish the model below par.
Just my experience..