1. Document existing views. Take photographs when you move in of the views that you want to preserve, noting the location and height of trees that may become a problem in the future.
2. Meet your new neighbors and discuss with them your desire to maintain good relationships and good views, so that they can understand your interest in seeing their trees do not become too tall or bushy as they grow.
3. You may want to offer to share in tree maintenance costs from the beginning; after all, it is the investment in your property you are insuring, as well as a future cordial relationship with the neighbors.
4. Continue your photographic documentation of the trees as they grow (if they do), and discuss any potential problems as they arise. Are the trees starting to encroach the on the view? If you've had success with 1-3, your neighbor is likely to be willing to trim the trees before they become a real issue between you.
5. Know the rules for your community or development, including the procedure for filing a claim, going to mediation or other dispute resolution methods recommended.
6. If you need to invoke the process, you will be armed with knowledge and with a paper trail of your efforts to preserve the view amicably.
7. And don't forget to try mediation first, before you go to court (most tree/view ordinances require you ask your neighbor to mediate before you may bring a lawsuit). If you do get to court, the judge is likely to send you to mediation anyway, so why not try first, agreeing to use a skilled mediator and even a mutually agreed upon neutral expert to advise you and the neighbor of how to remediate the problems to the satisfaction of both parties?
