Your lender will tell you that once you are under contract, these are things you should not do:
1. Do not change jobs or become self-employed
2. Do not co-sign a loan
3. No high credit card charges, or let them fall behind
4. Do not spend the money you have set aside for closing
5. Do not omit debts or liabilities from the loan application
6. Do not buy furniture or appliances
7. Do not make credit card inquiries or get a new credit card
8. Do not make large bank deposits without first checking with loan officer
9. Do not change bank accounts
10. Do not purchase an auto
To reduce the chances of loan denial, which could make you liable for a suit by the seller, make sure you listen to good advice.