There are great elves and faeries that like to come down in droves so it's not too hard to keep a few relevant creatures on board
So you cannot use one creature to pay for multiple sacrifice costs at the same time, nor can you play an instant that your opponent has already forced you to discard to still gain its effect
Tarkir: Dragonstorm has been fully released and we've got tons of great cards to consider for all kinds of formats like Commander, Five Color, Type Four, Highlander, Peasant and Pauper and loads more
All these creatures entering the battlefield means we should look for ways to exploit that
Scrying Glass RA08 Urza's Lantern 1 Artifact 3, T: Select a number greater than zero and a color
Second Sunrise Second Sunrise was a key ingredient in a combo deck called Eggs, best described as Longform KCI. Eggs would sacrifice Chromatic Sphere, Chromatic Star, and other cheap artifacts to draw cards, then get them all back from the graveyard with Second Sunrise