I admit that I am to blame for buying a lot of shit coins both in the past and even recently. But I will always continue to buy coins with the hope that I will find a gem in all the crap.
Because if you don't attempt buying any coin, especially when it goes against the belief of the crowd and you always feel that buying is a bad idea, you may just continue to spin your wheels and listen to the trolls. My belief is that if you don't buy anything but rather stick to the main coins, you will never win as you will just be playing the same ticket as everybody else and the percentage of winning anything is lesser in that case. You will never know what you missed out on. Even if you fail, you will have gained valuable knowledge of how to do better in the future. Thats why my slogan in life is He who dares always wins.

It means that if you dare, and try to do something different and be strong and persevere, you are almost assured of a win; but if you dont try at all, you dont even have a shot at winning.
These are my 6 basic pieces of advice when buying a coin. Note that they are not exactly a fullproof sure way of winning, or that I am right, but these are the only ways I see it and it is Who dares wins!
1. Buy when the prices are very low and sell when they are high but do not sell everything, always keep at least 25 percent.
2. Do not listen to the trollbox, they are not there to help you, rather they are there to fill their pockets with money, using nothing but their lies.
3. Always check volume, and the best place to do this is in the coinmarketcap, check the trend on the graph.
4. Many people will tell you that it is better to just keep buying bitcoins, holding on to them and forget about the rest but that goes against my two main principles. Just try to invest in some of them that you find interesting and that you feel have a good future. If you dont dare you will never win but if you put all your eggs in one basket and it drops, all your eggs are broken and all your investment will be gone.
5. Just like gambling you can lose everything, but once again dont put all your eggs in one basket, spread the risk.
6. Do not be in a rush to buy and sell your coins, rather be patient. It is the most important point in trading. You must be strong emotionally. Who dares wins!