First, every lender is different in regards to their requirements and what is most attactive to them. In general, these are things that make you offer more attractive:
Cash offer with POF
Clean Offer w/o contingencies - The bank will counter you anyways with an offer that will allow you to have an inspection period that will allow you to look for a cash end-buyer/prepare for your closing.
More Earnest $$ the better - makes sense right. But if you are not experienced and make a mistake, you may not have the ability with no other contingencies to back out = LOSING ALL THE EARNEST $.
Quick closing
Using the Listing Agent so they can get the buyer’s agent’s commission
Some Lender will require you to get a preapproval through one of their L.O.s