Two things that I absolutely despise when traveling are checking bags and fighting for overhead space on the plane. Unfortunately, it usually comes down to a choice between the two. Luckily, there is a solution. A couple of years ago, I invested in an underseat bag. Essentially, it is a smaller bag with dimensions designed to fit underneath most airplane seats.
There are a number of options, so I’ve kept this pretty brief. Look around and find one that’s right for you.
Samsonite - this is the one that I have been using for over two years. It's very basic and sturdy. The wheels do not rotate 360°, but it is still very functional. It's got a great space for a laptop and other electronics. I find that if I need to travel for more than two days, things get a little bit tight. It also works best if you only have one pair of shoes for the entire trip.
Tumi - without a doubt, this is the best on the market. Of course, it comes with a very hefty price tag. Unless you primarily take short one to three day trips, you're most likely going to need to have other luggage in your arsenal anyway. It really comes down to whether not you want to spend this kind of money. Tumi also sells numerous organizational system add on products to help maximize space. https://www.tumi.com/c/luggage/carryon-luggage
Travelpro Maxlite 4 - while it is not the same quality as the Samsonite or Tumi, this is a great option as well. It is less expensive, very lightweight, and does have a feature that the Samsonite does not. It has 360° spinning wheels. If you only need underseat bag a couple of times per year, this could be a great option for you. https://amzn.to/2A1Krkt
Of course, there are a few situations where this will not work. Obviously if you need to pack heavy or are planning to travel for more than three days, it's very unlikely this will work for you. Sometimes two days is a stretch depending on the climate. Also, there have been several times where I got on a plane and realized that there was a barrier or a bar underneath the seat that made it impossible for the bag to fit. Nothing is a guarantee.
Once you've picked a bag, you simply have to figure out how to pack efficiently and what to take. I'll leave that one up to you for now