To add on what niakulah said, brushing before and after wear is really important as dust and debris may get into the pores of the leather, in the long run this build up will cause the leather to crack especially where it creases.

Touch up cream and wax whenever there's scuffs. Reapply conditioner, cream polish and wax polish after every 10 wears as good practice.

My full treatment every 6 months is apply sole guard if soles are leather, clean, condition, cream and wax the whole shoe. Condition the welt and cream and wax sole edge.

Not wearing the same shoe continuously 2 days in a row is also very important. Let the leather to rest, wick away sweat and moisture.