What are the important methods, ways, tools have you learnt that make a big difference in your work or life? 1. software, 2. lemmas of math, 3. clean ways of maintain and tracing documents, or 4. effective recipes to strong project management 5. tools that make a great difference, eg, logmein, aescrypt, etc 6. webpages that make a grand difference, eg. mathworks central, etc 7. life-steering advices from veteran engineers, eg. my mentor once said "what is hard to code must be hard to debug". I adopt this principle in life as well.
Please share the specifics.