best advice i can give is go ride some easy greens or blues, even the bunny hill! and have fun with it. laugh when you fall, and get into. focus on figuring out how your turning regular and just slow it down and do it switch. just go slow at first.
If you really wanna go big, strap in switch and skate around one footed for a bit. Just get really comfortable lifting the board with your non dominant foot. get it used to being it front. do the lift switch(nice and easy, remember you always have your back foot free to the "chicken skate" off and on. and remember to laugh and have fun. I bet I look like a fool laughing to myself when i fall, but I swear youll never get down and out if your just rollin with it.
^ Also dont forget you you can always flip back around to your regular stance. This might also get you nice and comfy with switching back and forth.
Riding switch confidently was definitely my biggest accomplishment as a rider. you really realize snowboards are twin tipped for a reason.
It took a while to get just as comfortable as regular but the trip there is a blast and it only gets better.
nice and slow, and lets see those big turns!
EDIT: Im a avid believer that if you do alot of switch riding you should have an even stance, mines ducked out at 15/-15 extra wide and love it. A narrowed duck might suit you better, but Id at least reccomend trying 12/-12 out regular.