There are plenty of interesting and simple online tools which can be used to improve your trading results, such as the Relative Strength Index (RSI). This is just one example from among dozens of possible technical analysis (TA) options, and you will need to discover and decide which ones work best for you. You may need to paper trade to figure out the best TA tools for you and your strategy. Besides these sorts of technical analysis indicators, there are a few "tried and true" rules:

When investing in the stock market, you have to think long term and avoid the temptation to check your portfolio several times per day. All this will do is waste your time, stress you out, and increase the odds that you will make a big mistake and sell at the wrong time. Plan to set up automatic contributions to your investment so you can buy more investments no matter where you are.
Taxes like broker fees will cut into your profits, as will any penalties for failing to pay the correct dues. But, with so many differences between tax systems, knowing where you stand and what your obligations are isn’t always straightforward. The best free tips, therefore, will help you maximise your profits whilst remaining within the parameters of tax laws.
But building a diversified portfolio of individual stocks takes a lot of time, patience and research. The alternative is a mutual fund, the aforementioned ETF or an index fund. These hold a basket of investments, so you’re automatically diversified. An S&P 500 ETF, for example, would aim to mirror the performance of the S&P 500 by investing in the 500 companies in that index.
Bernard Baruch, known as “The Lone Wolf of Wall Street,” owned his own seat on the New York Stock Exchange by age 30 and became of the country’s best known financiers by 1910. Mr. Baruch, while a master of his profession, had no illusions about the difficulties of successful stock market investing, saying, “The main purpose of the stock market is to make fools of as many men as possible.” According to Ken Little, author of 15 books on investing and personal finance topics, “If you are an individual investor in the stock market, you should know that the system stacks the deck in its favor.”
Buy in thirds: Like dollar-cost averaging, “buying in thirds” helps you avoid the morale-crushing experience of bumpy results right out of the gate. Divide the amount you want to invest by three and then, as the name implies, pick three separate points to buy shares. These can be at regular intervals (e.g., monthly or quarterly) or based on performance or company events. For example, you might buy shares before a product is released and put the next third of your money into play if it’s a hit — or divert the remaining money elsewhere if it’s not.