It is hard to determine the best level one should use, as it mainly depends on the trader's strategy and the actual vision of upcoming market moves. As a rule of thumb, the longer you expect to keep your position open, the smaller the leverage should be. This would be logical, as long positions are usually opened when large market moves are expected. However, when you are looking for a long lasting position, you will want to avoid being 'Stopped Out' due to market fluctuations.

Let's say a trader has 1,000 USD on their trading account. A regular lot of '1' on MetaTrader 4 is equal to 100,000 currency units. As it is possible to trade mini and even micro lots with Admiral Markets, a deposit this size would allow a trader to open micro lots (0.01 of a single lot or 1,000 currency units) with no leverage put in place. However, as a trader would usually be looking for around 2% return per trade, it could only be equal to 20 USD.
In the world of trading, it means you can access a larger portion of the market with a smaller deposit than you would be able to via traditional investing. This gives you the advantage of getting greater returns for a small up-front investment, though it is important to note that traders can be at risk of higher losses when using leverage. In finance, it is when you borrow money, to invest and make more money due to your increased buying power. Once you return what you borrowed, you are still left with more money than if you had just invested your own capital.
With Equivolume, you can plot price and volume activity on a single graph, instead of having volume added as an indicator on the side. This tool draws the bars following their traded volume at a precise point in time (the wider the bar, the bigger the volume). That creates a clear visualization of the volume increase or decrease of an asset’s diagram. A very handy feature for those strategies whose key factor is volume. How to change your table into Equivolume