The first thing to know is that it a lot easier than it apparently looks. This is how it should sound, more or less, using English phonetics (and it might help to remember that the first syllables for both names approximately rhyme when you flatten it a bit):
LAY-sha PAY-len
Now say it faster so it doesn't sound so clumsy. :-) Rule of thumb: If you talk with me in person, don't be afraid to inquire (multiple times if necessary) about how to say my name. I'm not offended in the least, and it is much better than being called "Hey YOU!"