Once you have completed your tower to your desired height, width, or however you like it, you know that you have to keep rerenting the condos and offices and all that on the 1st of the month so-to-speak.
I found out that it is best to keep your retail shops prices at their minimum price so you have less to rerent.
If you have hotel suites or twin or single rooms, after people have rented them, raise their prices to the highest it can go in the morning so before they leave; you will have allot more money.
With the condos, when you have to rerent them, try to get the highest price possible so again, you make more money. But, the real pay off is the offices.
When you have to rerent them, raise their prices to their highest and keep it that way until the next rerenting day; when you have to rerent them (conditions are terrible) rerent them and set their prices to the highest again.
If you don't want to go through the trouble of rerenting rooms, keep prices of whatever needs to be rerented to their lowest.
NOTE: you will make more money using these methods but, if you keep their prices low at all times, you will be in debt.
Be patient and you will have the best tower possible without problems.
My tower is now 10 years old, I have about $1,000,000,000 and about 15,000 people. It is possible.