They are helpful and almost standard practice today, however, from my experience one of the frustrations in our decision process was not being clear on space allotments after seeing so many homes. 

Also, in your numbers have you allotted for insurance, garbage, any utility, lawn service, bug service, vacancy etc.?

The "gain" you are left with after you do your calculation needs to go into another investment in the time frame allotted (usually 180 days).  

I'm still new to this as well...But reading has definitely given me allot to get started with. 

So basically, you probably won't get to pull that money out within that time frame allotted.

If your ARV is $185k, but all of those comps have granite countertops, stainless appliances, hard surface flooring, recessed lighting, etc, you have to ensure that you are providing a similar finish and ensure that it is reasonable in the budget that you have allotted.

Read the site that Tanya gave you, there's allot more variables than you think. 

Discipline yourself to save the amount you would have spent on rent each month for maintenance and capital expenses (set up an allotment from your pay).  

Give this "job" one day out of every 30, and focus on keeping the work to within the allotted time.

I've read allot about improving your area to increase property value and with the support of my whole street I know it can be done.