Here’s a small piece of advice, which I would like to have learned earlier: save the date.
Put the date in filenames, but don’t stop there! Put it on everything: journal entries, food in the fridge, every document you write, and each box you send to the storage unit.
Always use a consistent date format. If you choose an all-numeric format, I recommend the international date format YYYY-MM-DD (ISO_8601) for all the obvious reasons.
The advice can be expanded to save more metadata about the things you work on. For example, keep text files documenting progress on projects big and small, including all the dead-end paths you took — so you don’t go down them twice.
The date is the fundamental piece of metadata. It helps you sort things, find things, and remember things. It only takes a few seconds to write down. It can save hours.