I use the Dyson Airstrait and it’s incredible.

GHD pro. I have been using mine for about 8 yrs now. well worth the investment

The GHDs are darn expensive, though... I have a CHI titanium plates from Ulta that cost around $70, and I use it on wash day after blow-drying for the silk-press effect (at around 370 degrees), but I also have a less expensive ceramic plate iron (goes down to 285 degrees) that I use to curl the ends because they don't need that much heat. If you buy one that goes up to 450, I highly recommend using it at lower settings and finding out exactly how hot you need it to get the results you want, don't push it to the maximum. Especially if you're still practicing and learning how you want to use your flat iron, spare your hair the heat damage!