How should you go about making an offer on a house? First off, when you make an offer, if you're not already preapproved for a mortgage, make sure that the offer is "contingent" on your securing financing. It should also be contingent on the property being cleared by the home inspector you hire.
Setting a time limit can also be a good idea. You can make your offer good for 24 or 48 hours, preventing the seller from stalling and waiting for a higher offer.
If you're serious about the offer, you can make it more enticing by giving your agent an "earnest money" deposit toward the price of the house. It can be a few thousand dollars or even as much as 10% of the price, depending on what you're comfortable with. Your agent should apply it toward the house purchase if the sale goes through and convert the check into confetti if it doesn't.
Keep in mind that the state of the market should influence your offer, too. If it's a seller's market, you as the buyer ideally shouldn't have too many contingencies in your offer. If you do, the seller might just move on to the next offer. In a seller's market, it can help a lot to be preapproved for a mortgage and also put down a significant deposit on the house. These show the seller how serious and determined you are.