Everyday you can find opportunity to train your pooch. I am not professional, just sharing my experience with my 10 (soon to be 11) year old amazing Gigi.
We were having dinner at the dining room (which I don't always eat there). Anyway, I would prefer Gigi to sit nicely and not beg for food. So rather than having to tell her sit or lay down wherever she wants, I put a little bed (or you could use a blanket) in the spot I want. So she knows exactly where she should go. This way I am helping her exactly where to go and that I don't get annoyed. :) And she stays in her bed watching me eat (ha) almost the entire time. It would be very helpful if we have guests, so she knows where she should go. :)
A selfie with my girl. I take all opportunities to have pics taken with my girl.