You may be so psyched about kissing this person that you throw your whole face forward at theirs – not a good idea. You don’t want to be kissing them so hard that it’s not comfortable for their neck! Along with your timing, you can vary up your kiss pressure so it’s not exactly the same ol’ thing from start to finish.
Start with some lighter ones and you can try getting a little more pressure-friendly as you continue. Gauge how your partner is responding and go from there. Most importantly, just relax and enjoy it!