In the real world, it means presenting exclusively as your desired gender (though I think wearing your old guy jeans and T-shirt for painting is probably OK), identifying yourself only by your chosen name and requesting others to use it and the appropriate pronouns, only using the appropriate washrooms, etc. Basically living exclusively as your true gender, with no lapses back to your former gender. It doesn't necessarily mean that your paperwork has caught up with you, but would suggest that you are in the process of doing so.
I take off the wig at home and remove any makeup (though I don't always wear makeup outside), and I have to shave every morning. I don't see any reason not to consider that full-time. Many cis women do the same things. My wife calls me Kathy and refers to me with feminine pronouns. When I make phone calls, I identify myself as Kathy. My old name is permanently retired.
The story is different when talking to government bureaucracies. Since I have a British birth certificate, I have to follow their rules for my gender change, which require two years of RLE. They require documentation to support one's claim. I did take copies of my coming out posts on Facebook and elsewhere, but I don't know if they will accept that. The one I am sure they will accept is my legal name change. Unfortunately, that came three months after I started RLE. So I might end up doing two years and three months before I get my official gender change.