When inviting someone to an offer, it's crucial to communicate it with enthusiasm and excitement. You want them to feel special and that you're offering something of value.
Download the sample scripts and memorise it so that when you invite, it comes out of you naturally- focus on the person and not on what you are saying.
There is also a welcome letter. Customise it, make it your own, but be sure to include these special touches as it delights your prospects and lets them know that they are special.