Wrote letters to all my representatives, will write more in time. I am glad that here in New York state, both my assemblyman and state senator voted against Cuomo's gun bill. I've written Boehner and Harry Reid, will have to write and call them both too.
I read an article saying as of late, calls to Reid's office are 2-1 against Obama's proposed bill. Call and write as the numbers do count. Call in particular as calls cannot be ignored as e-mails can, which can be deleted. Contacting does work if the numbers are large enough. In California for example, there was an effort to ban the "bullet button" device on AR-15s in that state. The effort failed due to resistance from California gun rights people (now the same guy is apparently attempting it again from what I've read---he will have a better chance this time as the legislature is now totally controlled by Democrats).
Contact the following:
(regarding state-level gun control)
Your state legislators
The leaders of your state legislative bodies (regardless of their party)
The leaders of your state Republican party
(regarding federal level gun control)
The leaders of the national Republican party (Speaker of the House John Boehner, Senate Minority Leader Mitch McConnell, etc...)
The leaders of the national legislature (Senate Majority Leader Harry Reid, Speaker of the House John Boehner, heck even hit up Nancy Pelosi just for numbers purposes!)
And BE PROFESSIONAL. Don't write with a bunch of typos and don't sound like a nut or anything, be professional and courteous.