Last week I took Volunteer Deputy Registrar training at the Llano County Elections office. To find your local Elections Office, you can search with the term "(your county) election administrator".
A VDR can give anyone in any county in Texas a postage-paid mail-in registration form. If assistance in filling out the form is requested, the VDR is responsible for getting the form to the County Election office within five days. You take an oath not to advocate for any political party while registering people. If you want to register voters in another county, you don't have to take the training again, but you must request a certificate for that county from its elections administrator.
The forms are very simple and the training is designed to make sure you treat every potential voter fairly in a non-partisan way. The Texas Volunteer Deputy Registrar Guide, Training Materials (pdf) and Exam (pdf) are online to study in advance. The class and exam take about an hour, in person, at which you receive forms and your certification. Typically in Llano County, classes are given once a month, but by request the Election Administrator may be able to schedule classes to suit the needs of groups or individuals.
This weekend I participated in a community event, the 2018 Kingsland Aquaboom as a Llano County Democrat with no partisan signage. It was a great day and I feel I've contributed my little bit to the political process.