I'm also a big fan of using the first letter of my variables to indicate what type that variable is. That way, if it's a large function, at a glance you can tell whether you need to convert a variable to a different type or not. I also like to name my variables such that I know roughly what their purpose is. If they are temporary, I usually suffix them with temp. ie:
int iTemp, iCount, iSum;
char cTemp, cChoice;
float fProduct, fSalary;
double dProduct, dSteemReceived;

Whatever method you use to define your variables, trying to be consistent can same you a lot of hassles.