Read Section 21-2101 of the D.C. Code. This section contains a form for a valid power of attorney in Washington D.C. You do not have to use this specific form. However, your power of attorney document must substantially comply with the statutory form.
Edit the form so that it states "I [your name and address] appoint [first agent's name and address] and [second agent's name and address] as my co-agents (attorneys-in-fact)." Insert the appropriate names and addresses.
Initial the powers that you want your agent to have.
Write instructions in the "Special Instructions" section. Consider how you want to resolve any disagreements between your agents and write the resolution down here.
Sign the power of attorney document in front of a notary public. Unless you have modified the document otherwise, the power of attorney is effective immediately.