I went across to the Asian side twice, this was my first day and much more of a full day exploration. This day was spent mostly in Kadikoy, which I think is where most tourists go. It is accessible by ferry or bus (if you go the long way over the Bosphorus Bridge).
For about 10tl you can get your shoes shined right when you step off the ferry. I was so mad I didn’t wear leather shoes this day, so my tip to you is to wear your leathers and get them spruced up.
The whole Kadikoy area near where the ferry lets off is really cool. Take the time to investigate, you will find a secret multi-level book bazaar, a market, tons of food, bars, and shopping.
Markets are by far my favorite things about traveling to new places.
A stop for some Borek and cai with friends.
Kadikoy street art
Almost the entire coast line in this area has parks where you will see many young couples making out. Head to the nearest park, and pick up some beers to sip on while watching the sunset.
I recommend going to Viktor Levi. Go with a small group and order bottles of the house wine, which is fab. We had multiple bottles, appetizers, entrees for around $20 each or 55tl. For a night cap, check out Karga which is right around the corner.