Southwest airlines is running another sale if you purchase by April 19th, 2018 and you fly between  4/24/18 – 6/13/18 and 8/21/18 – 10/31/18. Out of Houston it looks like the cheapest fare is to Corpus Christi at $49 one way but there are some other decent fares. Click below for the deals page. Southwest Airlines deals 

If you are wanting to go to Europe Aer Lingus has summer sales for airfare to places like Dublin for as little as $619 round trip (there are restrictions involved. You can also do a stopover for free in Dublin during your trip. You will need to book by April 4th at 7pm ET to get this deal. Aer Lingus is the national airline of Ireland and it is a good airline to fly. https://www.aerlingus.com/html/en-US/home.html

If you purchase by April 2nd you can get fares as low as $20 one way on Frontier if you fly on a Tuesday or Wednesday. From Houston it looks like the fares are around $30-35 one way to Philadelphia and Raleigh-Durham. https://www.flyfrontier.com/ways-to-save/online-deals/  

On this page I will alert you all of any good airline deals that I recommend you give it a shot. Watching for discount airfare is part of how Donna and I are able to travel as much as we do.