When track is imprecise, should I add the way and mark a fixme, or add nothing?

Hello (again).

When I do mapping, as I currently have no GPS tracking unit, I use geotagged pictures, aerial imagery and my own memory, but there are always parts under trees that I can only roughly map, as I cannot take a geotagged picture of each single step. When it is the case, and even as a general question: should I

1. add data, even imprecise, and tag a fixme on it describing the things to be corrected, or
2. do not tag anything, possibly leaving only a note describing the data to be added.

I would say the first possibility, as imprecise mapping is better than no mapping at all IMHO, but that leads to inconsistent elements as unconnected waterways made of only some isolated nodes, like when these waterways are mapped only on the small part crossing the highway=* the mapper followed, or kilometers-long straight on ways. I assume that part is up to the renderer, but I'm not sure, so I'd like to have a confirmation on that.

Awaiting your answers,

Regards.