In addition to personally writing directly to the elected official, you might choose to use various apps and social media formats to quickly contact lawmakers. Here are some of the more popular platforms:
RESISTBOT allows you to use your smart phone to turn your text into an email and deliver it to your officials. Can also send fax or postal letter. See https://resist.bot
5CALLS let you pick your issue, call your rep, and record your result. See https://5calls.org
CAUSES is a site where you can learn about bills going through Congress, see what others think, and then act by telling lawmakers how you feel with email and video messages. See https://www.causes.com
FACEBOOK groups like IndivisibleMartin and The Safety Pin Alliance help to inform you and often recommend specific actions to take. Also, in Facebook you can post a video or news item on your own profile and this may motivate others to take action.