I have two very tiny shrine-like areas in my 2 small homes. In my main home I have a small alter table from Nepal with artifacts from my travels, special stones or small gifts someone special gave me, a candle, and some hand chimes.
These areas are where I meditate. I also have Dali Lama’s photo, a few prayer scarfs given to me in Nepal, and mandala paintings I made at a retreat; at my desk. Helps me be calm and centered in that space.
I try to create a calm, peaceful living environment all around me with music, lighting, and good aromas(incense, diffused oils) so that friends, family, and workers in my environment feel the ambiance of peace- not any particular altar room.
As far as offerings- I only offer the merit of my yoga practice most days. And blessings? I only occasionally ask for my children or someone that I know is struggling ; to be blessed. I do not really believe in asking for things while I am practicing yoga or meditation or any spiritual practice. I will be open to hearing in this forum why others find it useful.