It may help if you understand where the word comes from.
meid = maid, girl
Dutch speakers love to add diminutives to everything, in this case:
meidje = [little] maid, [little] girl
As this word was so common, a sloppy pronunciation turned into a separate word:
meisje = [little] girl
Hi, you can try to break it down sound by sound maybe.
"m" at the beginning of course
The "ei" sound sounds like "ay"
The "sj" sound in Dutch sounds like "sh"
and then just finish it of with "es"
I don't know if that will help. Otherwise you could continue practicing until it becomes second nature!