Launch the DIRECTV App on your phone. If you don't have the DIRECTV app installed, download it here.
If you know what you want to record, just tap Search and type in the name of the show. You can also browse shows by Channel or by Date & Time.
Tap any show and select "On TV".
On the next screen, tap "Record". If you selected a series, you will have the option to either record a single episode or record the entire series.
Select the DVR you want to record to and tap "Record".