How to locate a dryer exhaust vent

What you've done sounds fine.

One thing to look for though is that your connections are the right direction. The female end of each tubing should be on the end closest to the dryer. This prevents lint from snagging on the sharp metal on the way through the vent system and creating a clog (a big fire hazard). With the female ends upstream, there won't be any sharp ends to catch on.

You want the shortest distance possible, and for everything except perhaps the dryer connection, you want to use rigid metal tubing rather than the flex tube. The rigid tubing will resist the airflow less and collect less lint. The better airflow from rigid tubing and shortest distance will make the dryer more efficient. If too much lint builds up in the vent, you have a fire hazard in addition to longer drying time.

I'd also suggest having the exhaust somewhere you can reach with a small step ladder to make it easier to clean the vent. So I'd run it down through the floor rather than up through the ceiling, if possible.

Finally, when you install the vent opening in the side of your home, make sure it's weather tight. If it's vinyl siding, you can get a removal tool (it's a flat blade with a hook on the end that pulls two pieces apart). Take off a few pieces where you're working, securely attach the vent, seal around the edges (not sure if Tyvek tape is good enough, they make a rubber adhesive membrane for window openings), install a few pieces of J channel like you have around windows and doors, and cut (measure twice) and reinstall the siding. Vinyl siding screws should remain loose (should be able to slide a fingernail underneath) so that it can expand/contract with heat/cold.