I have crossed the pond, the Atlantic 10 times. It is a rather long trip. The first time was probably the worst, the flight from Orlando to London was scheduled to leave at about 9:00 at night, the plane was late arriving, then it needed to have a hydraulic pump replaced. We left at about 2:00 AM. Then I tried to sleep on the packed 747. It was a very uncomfortable flight. Over the years I have learned how to make the flight more comfortable.
Most flights from the USA to Europe, are overnights. Unless you are unusually talented at sleeping sitting up on a crowded plane, the overnight flight going over is the worst part of the experience. In ten trips, I have had one that I slept more than 3-4 hours on. Some tips: Leaving earlier in the evening is better than late. If you have a choice of a 6:00 PM departure or a 9:00 PM departure, take the earlier one. If you leave the east coast of the USA at 6:00 PM, and you have a 7 hour flight you get into London at 1:00 AM east coast time (6:00 AM local time in London with the time change.) If you take the 9:00 PM flight, you arrive in Europe at 4:00 AM east coast time. I can stay up until 1:00 AM a lot easier than 4:00 AM. Don't plan on sleeping on the plane. Take a book or kindle, your favorite music, play the electronic games. Take a pillow or two and grab one of the airline pillows and blankets. Nest in and get comfortable. I wear ear plugs when I am not listening to music or watching the inflight movies. If you drift off to sleep great, if not, treat the flight lake a late night out, when you get to your destination check into a hotel and take a 2-3 hour nap. When you make reservations for the first night, insist on an early (ie: morning check in time.) Even if you have to pay extra, it is worth it.
Now from the upper east coast of the USA, you can get day flight to London, or Paris. These go out of Washington DC, New York or Boston. From DC to London, is a 7 hour flight with a five hour time change, so you leave at 9:00 AM and get into London at 9:00 PM the same day. If you can do one of these, it is just like a long day at the office. I have only made that work once. It was bliss.
The trip from europe to the USA is always easier for me, because they are all day flights. It is a long flight - but really no worse than a 10 hour day in the office. Ideally take at least one extra day off after you get home to recover from the trip.
It is possible to cross the Atlantic by water. Cunard has weekly transAtlantic service, sometimes the one-way fares for an inside cabin are under $1,000. Another option for a one way, is a repositioning cruise, the cruise lines move ships from the Caribbean to the Mediterranean or Scandinavia in the late spring. I have seen 7 night cruises from the east coast to Europe for $700 per person. If you have the time, this has to be a wonderful way to cross the Pond. Much more comfortable than what my grandmother did in 1912.