It's all about developing your priorities, and understanding your budget!
For each service-ingredient (music, photo, venue, flowers) figure out what you absolutely need; what elements you would really want to include if possible; and what bells and whistles you would include in your fantasy dream version. Develop a 3 tier model for your brainstorm.
Apply this 3 tier brainstorm to any service-ingredient of your wedding.
Here's an example for mus:
1. Need: Music for ceremony and reception.
2. Really Want: Live music for ceremony. DJ dance party for reception. DJ can play some country, but no music from the 80s.
3. Fantasy Dream: Live string trio for ceremony playing Iggy Pop and traditional New Orleans jazz. DJ with skills as balloon animal artist for reception. Must play danceable country music, no 80s music, big band swing, Haitian party music, old skool rap, and take karaoke requests. Up-lighting necessary to turn entire room purple, fog machine for dance floor, bubble machine for stairway, LED hologram monogram of bride and groom's names on ceiling. DJ should tell jokes and give prayers.
This is meant in the spirit of help, and of course humor. But it's worth noting that a lot of service providers (vendors) are ready to sell you well into (and beyond) your fantasy dream, even if it's more than you need or really want.