I generally agree with you but I wanted to add some thoughts to it.
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.
there are times that the price is low for a reason, and it will continue being low and go even lower.
and I don't generally agree with not selling everything because most of the coins don't really have any kind of future so they will die sooner or later, so it means that rise may be the last rise and you last chance to sell.
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.
I agree.
you should never listen to anybody else except yourself. if you can't decide for yourself then you better not trade.
3. Always check volume, and the best place to do this is in the coinmarketcap, check the trend on the graph.
you can do it on your exchange site if it is a good one like bittrex or poloniex, their volume says all you need to know.
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 don’t 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.
many people say this because trading is not for everyone. not everyone can make profit with trading altcoin so most people are better off just buying bitcoin and holding to something that has a sure (at least 90% sure) future.
5. Just like gambling you can lose everything, but once again don’t put all your eggs in one basket, spread the risk.
this is completely wrong.
in trading you will never lose "everything" unless you invest in a scam coin with shitty code, but yet again such coin will not reach legit exchanges and you will only find these kind of coins in cheap, shitty exchanges like yobit.
in trading if you are careful and have a good exit strategy you will only lose small, but if you buy and go away without following on things then yeah you will surely lose a lot.
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!
+1