Base on my experience, its really hard to spot shitcoins, especially if they are still newly launched. Most of the shitcoins/ scam coins are exposed only after some time and that could even be months until you realized you are holding it.
Well, if we try to determine if the project is a shitcoin or not as soon as it launches, that is certainly not easy to define because the trading volume and demand of people is still not stable, besides, the next plan of the project may not be clear and launch, rushing in judgment just easily leaves mistakes and misses opportunities. At the very least, use a certain amount of time to consider, if it's a shitcoin, the value will drop relatively quickly over time and very little liquidity, conversely, a good altcoin will have good liquidity, the value can always go in a positive direction