Sannion recently blogged an excellent piece if advice that before you build a shrine you need to get to know your god through worship to discover how that god appears to you in a meaningful way rather than erecting general shrines. Even though he was speaking of Dionysos in particular, this is valuable for any god.
When it comes to Apollon I have a long history of throwing together shrines that attempted to squeeze in every symbol and sacred thing. More recently I discovered that the shrine I gad previously had little to do with my relationship with him. Pretty much the whole thing was tossed aside, and I had to spend some time considering how Apollon has revealed himself to me. It was these things that have become incorporated into my shrine.
For instance the main images on my shrine are connected to how he has revealed himself, and how my relationship developed: Lykeios, Pythios and Karneios primarily. Secondary is Delphinios ( recognizing Apollon as the Dolohin lord, leader of ships/souls) and Kithirados (with his kithara). In association with these my shrine has developed to reflect them. My shrine is flooded with serpents, wolves and goats consequently with only the smallest homage to swans and dolphins. Otherwise it is skulls everywhere that play a big way in how I have experienced him…the dragon resting upon skulls of the dead and decaying remains. The fiery one.
It is for this reason that I agree whole heartedly with Sannion. A shrine will not really be very effective in your worship unless it is constructed around how the god is to you. It is but a connection and a reflection.