Communicate. It doesn't matter if you're on location or working remotely. If you communicate clearly, understand things before you start work on them and get your message across then you will have success. For each new feature or task, make sure you understand what the outcome is expected before you start. I have wasted a lot of time the times I have not followed this advice.

Prioritize. Get your client to help prioritize their work. If they have a list of features to implement, ask which ones are the highest priority. Help them understand that you are only one person and that only one thing can take priority at a time.

Read. Read a book about your field for at least 15 minutes per day. At this rate you will finish one or two books a month and be far ahead of people who do not read. Be constantly improving your skills and learning new ways of doing the things you are currently doing. (I admit this is advice I have implemented for a couple years but have gotten away from recently in the last month.)

Your question might have been probing for the tools to use. The tools don't matter as much as the person behind the tools.