Go about your routine, but talk or sing about what you are doing with him either nearby or in a sling. This will not only entertain him, but help support important language skills that developing right now. If you feel like reading (say a magazine), read out loud... same effect as narrating or singing what you are doing. I know it sounds silly, but you can start looking at children's books with him. By 8 months my girls started to turn the pages for us, and by 12 months they would spend hours a day reading in our laps (no exaggeration).
Tummy time may be more entertaining if you put him on his tummy on the couch and you get down next to his face and talk and sing with him or show him toys right by your face. Don't worry if it doesn't last long- even a minute is OK, and will eventually grow into longer stretches.
We did infant massage with our first around that time. We took the class, but I'm sure you could look up online how to do it. Lights of any kind were a big hit, mirrors, reading books were big for us, music even what we love, different textures - I would have my son feel things around the house as we did stuff, paper - he loved to crumple the paper (newspaper was easy to do and he was too young to figure out how to put it in his mouth yet so that worked well), once he can hold his head up he might enjoy the bumbo chair as well.
I agree w/ the other posters. They LOVE interaction. And if he hasn't started already, the "real" smiles are coming really soon :)
i agree with julianovak they dont need a whole lot of play time right now. i put ariana under toys that hung over her head a lot. she also loved to sit on her changing table..dont ask me why lol. just talk to him and smile at him. they love to be interacted with the most.
well i always carried my DD everywhere with me.... when cooking when doing laundry.... they dont need "much" playtime now.... honestly dont feel bad. Dont expect him to "play" til hes around 5 6 months.