first you have to know who are your end users. once you get that thing clear then you have to contact them ( i prefer emailing) , then make them an offer and try to convince them that why they should buy the domain.
How to use Escrow services for payment. Like step by step details of if the buyer has agreed to pay theprice you want, how to proceed with the payment and invoicing details.
Also, maybe a comparison of Escrow services.