Don't max out on "affordability" based on income.  Leave a cushion and pay down the mortgage early to build equity faster.   And/or use the extra income for consistent investing.  The is MY short answer but I am not a financial consultant so take it for what it's worth... FREE advice.  LOL

I let the licensed mortgage broker address anything that has to do with financing.

I agree with Carol Williams .  This is sage advice. 

Get pre-approved! Then I let my man Jason E. Gordon give Mortgage Advice, I give housing advice...we stay within our licenses when it comes to advice.

Anthony Acosta - ALLATLANTACONDOS.COM nailed this one!

Don't buy more than you need. Just becasue you can afford it doesn't mean you need it.

I love Carol Williams' answer and I would add, refer them to your top lending professionals. They are a wealth of knowledge in this part of our business and I lean on them to get my buyers ready to purchase a home.

Hire a REALTOR® you trust and work with a qualified lender to make sure you truly understand the parameters of the loan.

Several folks have recommended, "pay down debt" but I recommend not doing that before working on the pre-approval.  In my market, there are many first time buyers that are so tight on funds they need to keep the debt and save the cash for closing costs and down payment.

My primary lender and I sit down with buyers together and work out the best strategy for them.  

Know your numbers! Work with a trusted lender and follow his/her advice.

don't stretch it to the limit...you need to breathe.... 

Talk to a financial advisor, mortgage consultant, accountant, tax/financial attorney. -Kasey

Talk with at least one mortgage lender.

pay off debt

Don't max out and consult with a professional about a budget.

Stay within their budget!  

Don't leave yourself house poor.  Home ownership is a blessing but if you are unable to enjoy life due to the monthly payment you have made a major mistake.  It is not how much you can afford, it's how much can you afford and still enjoy life.

Careful not to overspend because the mortgage broker approved you for an amount he said you can afford. You are in charge of your finances, not the mortgage broker.

At the risk of sounding "self serving" the logical first step in the home buying process is to get pre-approved. Not only does this process provide clarity for the Buyer in terms of their ability to perform on the open market, but it begins a strong dialog with their Lender. A good Lender will utilize this opportunity to dig deeper into identifying a reasonable budget for the Buyer to consider, while elaborating additional monthly costs associated with home ownership (taxes, insurance, HOA, etc.).  The following AR Post details the initial first steps:

http://activerain.com/blogsview/4899160/pre-qualification-vs-pre-approval-vs-cross-approval-vs--10k-assurance

Thank you for the mention Thomas J. Nelson, Realtor,CRS,ePro!

Have 3 lenders you work with that know what programs are out there.

Thanks for sharing Mike Albert.

Never maximize your potential lending limit, start small and work up to the dream home.

Buy less than you qualify for.

Get pre-qualified.

Not a mortgage affordability, but the whole loan process: read all disclosures and check all numbers carefully, so there are no surprises when you are about to close. I just had it with BofA who hit my client with outrages closing costs that were not clearly disclosed. Just disgusting how they work, promising low rates and 0 points, yet, they are always paid well, do not make mistakes about that. 

id say don't max out on the pre approval... if possible pay down some debt before making the purchase 

Just because you qualify for more, doesn't mean you can afford it.

Regardless of the amount that you are pre-approved for, only spend what you can comfortably afford.

Don't rent but if you insist, save your money. Reduce expenses as well

Do not max out on the approved limit.

Consult with a local mortgage broker.

Consult with a qualified mortgage professional who can provide guidance about the best program. Be sure to consider your personal budget when considering your monthly expenses

Consult with an experienced loan officer who can provide a variety of options and help select the best alternative for that buyer!

Get advice from a top mortgage professional.