My choice is kind of combining between 'whenever I stop being lazy' and 'finally draw their 'good' portrait once'. (good means non-chibi with full paintery-ish shading and I have like, thirty OCs who are stuck in this process. They got everything ready EXCEPT their portraits because I procrastinate like a world champion. )
Even so, there are still several OCs I have yet to upload to TH although I already have a few art piece of them because I'm really lazy at writing their history section. When I make a profile for an OC on TH, I like to make it as complete as possible, which means their history needs to be written at the same time I upload them. This is especially exhausting for Hetalia-inspired OCs because it means I have to write a summary of several hundreds to over a thousand years of history in one go.