Here’s how I do it if my watch, phone and iPad are not to hand (which is very rae these days) and I’m at my work PC.
First of all, enable the Reminders Import setting in Drafts. I use a reminders list called “Drafts” to import from.
Next, either create an account for or login to IFTTT (a free web automation connectivity service). If you don’t already have them set-up in IFTTT, enable e-mail as a service and iOS reminders as a service.
Create a new applet in IFTTT that takes an e-mail (from your connected e-mail address), with a tagged subject line (I use #drafts as my tag) and creates an iOS reminder based on the e-mail’s subject line.
When you e-mail to the firstname.lastname@example.org e-mail address from your associated e-mail account with appropriately tagged subject line, the IFTTT applet will trigger shortly thereafter. This will create the reminder. This will sync shortly after that with your iOS device (usually within a few seconds given decent connectivity). When you next open Drafts, it will check for reminders to import and create a new draft based on the subject line you mailed (excluding the IFTTT tag).
Hope that helps.