regulation, and check the review on the internet but find a good website for review( forex peace army is not a good reference, they make brokers pay to put good reviews, and if they don't pay they put them bad review), sent me a private message if you want to discuss more
Depends on what matters to you. Regulation is important, but if leverage is important if you dont want to invest too much. Most brokers offer leverage 1:500 but I trade with M4Markets for their 1:100 leverage
The most important factor to consider in a broker is Regulation (ASIC or FCA), and you can check about the broker on several forum sites for reviews based on other traders that have traded or currently trading with them.
There are a lot of factors that matter like the broker’s platform, spreads, commission charges, broker’s reputation and the market analysis tools. But the order execution speed is one of my primary requirements which I found fulfilled with hankotrade.