*Don't keep it parked out under the sun for prolonged periods. If you have to do so, cover the windscreen and open the windows slighty.
*When parking at home or when it's not being used alot, keep the windows slightly open or else you will experience fungus growth on the leather upholstery and if you don't clean it out immediately, it will leave nasty white spots around.
*Use a leather polish from time to time.
*When getting into the car, try to aim your proud cheeks right into the center of the seat. I have noticed how some seats have wrinkles on the side part because they just slide into the seat by sitting on the side and so on.
*Also, does your Civic come with full leather or half leather (center part is fabric, like the vezel/GP5s)? If it's full leather, try not to scooch around alot, sit steadily like a rock.
And no, constant cleaning & conditioning isn't necessary. Maybe give it a little clean & polish with a leather care product once every month or so depending on usage.
EDIT: I use this badu, OneStar Interior Polish 225ml, normal stuff and gives the leather a nice subtle shine. Don't apply in excess though. That's about it!