I'll add a few blogs below on ideas to increase revenue and decrease expenses but will share w/you one example we deployed last spring in a 320 unit apt community in north Dallas.  

Roughly ~6k and it decreases with the annual rent growth.

If you are taking a negative cash flow, it is usually because you have a strong plan for adding value either by increasing the income or decreasing the expenses.In the mean time, I strongly suggest finding a property evaluation tool / calculator that you like, and start evaluating a few properties each week.

Either increasing your income or decreasing your expenses will help you save up faster.

After the flood, I would expect market value of homes to decrease by 10-15%.

I ran the numbers for my business to see that we were losing money at $45 a cleaning and raised it to $70-$90 depending on the bedrooms and we have not seen a decrease in bookings after raising the cleaning fee.

On the flip side you  increase your equity, which decreases your risk of being  upside down in the event of market correction.

From my research you basically appear in front of a code enforcement hearing board and pray they accept to decrease the total lien amount or forgive it... however its entirely up to the board (atleast in Miami).I've talked to my lawyer and he stated the same thing however I've been hearing alot of local investors talk about forgiveness from the enforcement boards. 

Paying down a mortgage decreases cash flow it does not increase it due to the lost opportunity value of cash.

Everyone else's recommendations of sloping the earth next to your walls away from the house (can be accomplished with flower beds near the walls - avoid plants w/ long roots like trees), adding/fixing gutters, extending roof overhangs, and subterranean drainage are all steps to take to decrease water infiltration.Nowadays we ideally insulate and waterproof our basements from the outside - but that's more work than it's worth for a flip.