You can hire professionals to move everything from a storage unit that you have packed yourself, you can hiring a moving company Washington DC to pack only specific things and then you can hire a company that will do everything for you. Depending on your needs for a move, find at least 3 or 4 companies to get an estimate on the specifics of the job. From here it will be easy to compare the services offered, the insurance and legal paperwork confirming their business, and give you time to check all references provided.
First, when you have the movers come over for an estimate, show them everything that you intend to move. Individually wrapping glasses and picture frames is different then moving only furniture or larger items. Show them what the backyard looks like and if there is a garage, what items will need to be packed. You can only compare the items that all movers are aware of. When they come over for an estimate they will take note of stairs, square footage and number of rooms. Look for this in your estimate to confirm what they saw.
Secondly, there should not be a major disparity in the costs if you are hiring a reputable company that has been in the business for at least 10 years. Next, when the mover has given you the estimate they should provide you with the full details of their company such as full name, address, email, website information, USDOT (United States Department of Transportation) and their MC (Motor Carrier) license numbers. State and Federal agencies have requirements that movers must disclose to you in pamphlet form. If they have not provided all of this information, immediately take them off your consideration list as they may be a fraudulent company.
Lastly, decide on the moving company Washington DC that gave you the best estimates and can provide the best service. Confirm with the state departments that they have the proper insurance and legal licenses required to conduct business in your state and the state you may be traveling to. Remember to put your signed contract in a brightly colored folder so that on moving day you will always be able to locate it.