Version control - not GIT, which is a tool, but the discipline to version control whatever you can. When I was in the uni I was writing software for my end of s

Version control - not GIT, which is a tool, but the discipline to version control whatever you can. When I was in the uni I was writing software for my end of studies project on a computer whose hard drive died. Of course, I had backups, etc. but I was able to keep working in less than 2 days because of good old CVS. Years later, I put an obscure Netcool event manipulation under version control - and added tags for version - and discovered (months later) some events were kept forever in memory before a certain version - I don't know how many $$$ it saved, but at least we needed double the RAM (in 2008-2010) and that meant switching from Sun to Fujitsu servers...