1. It is generally recommended to use natural gravel for the aquarium. Colored gravel can be used, as long as it is professionally made, certain cheaply made color gravels can be toxic to fish in your aquarium.
2. You should always take the time to acclimate your fish to the aquarium. Acclimating your fish will get them used to the environment of the aquarium. Adding fish directly can be too much a shock for your fish and can pose health hazards.
3. Provide plenty of places for your aquarium animals to hide. Studies have actually shown that the more places a fish has to hide, the less likely they are to do so! Hiding spots also provide safe spots of refuge for smaller fish in the aquarium