Write a clean offer. In other words don't ask for too many contingencies. Don't ask for long escrow, or large repair dollar amount. Zero repairs, if possible.
If financing, be prepared to show proof of funds, for down payment. If you are offering more than list price, be prepared with cash to cover the difference in price and appraisal. Be pre-approved with a direct lender.
And, give yourself some room to bid. If you are pre- approved for $150,000, look at homes in the $145,000 or less range. Don't put unnecessary pressure on yourself. The right home is waiting for you. Trust you will find it.