How many of us have had customers come in who are shopping for housing who have not yet pre-qualified?  

Of course we  prequal them ourselves to determine their buying capabilities, suggest that they work with a local lender to get a prequal letter (sometimes even getting them on the phone with a lender right then and there). 

Then we work with them, find the right property, write a contract, get it accepted, and work through any  contingencies  towards a successful closing.  

And what do our clients do???   They are feeling so good, and so excited, they go out and buy themselves a new car, or a houseful of new furniture for the new place, and they blow up their debt to income ratio and boom the deal is shot. 

I always try to counsel my customers/clients on the dos and don'ts during the loan process.  I also try to give them an idea of how credit works.   Of course some times everything you do or say falls on deaf ears but  you have to at least try!  I have saved this link to this post by CBS News  because I thought it had a great overview of credit and how it works  that  I share with them.  You might find it helpful too.  It is pretty basic, nothing fancy.   

http://www.cbsnews.com/stories/2003/04/29/earlyshow/contributors/raymartin/main551521.shtml