> by the end of the day I'm usually feeling so exhausted that I seem to struggle to do more then lie down as mindless zombie. I've personally found that exerci

> by the end of the day I'm usually feeling so exhausted that I seem to struggle to do more then lie down as mindless zombie. I've personally found that exercise helps stop the zombie symptoms. Which helps me focus after work hours. For developing skills outside of work, try making little projects: games, simple apps... Etc. Having a small scope and clear goals will give you motivation to complete them and in turn hone your skills.