There is no such term as normal in launching a new coin. It's totally your decision what kind of building process of a coin to choose and all of them would be normal.
If you have enough funds for your coin development, for adding it on exchanges, for marketing, advertising and so on (probably significant amounts), if your coin have significant advantages over competitors and have a growing community already, you probably don't need any ICO.
But if you have only idea or some basic functionality, ICO can become a great tool to get a huge leap on the start of your coin's life. ICO is a great combination of funds rasing, marketing, advertising and a way of community engaging at the same time.
The more interesting is that even for the already popular coins ICO can give all the same profits as for the new ones but in a times higher values and in a very short period of time. What is have to be done for years to develop a coin in a usual way, ICO can help to do in a few month. If summarize I'd say that ICO is not a "must" but rather "definitely should consider about" feature for building a new coin.