When selecting a broker be methodical. Important areas to consider are their reputability, their regulator and their commercial features.
For reputability, give preference to older and larger brokers.
The regulator has a big impact on how much you can trust your broker. A broker regulated by a tiny government office in a tiny town on a tiny island should give you a tiny level of trust. Check the corruption index score for the country where your broker is headquartered and where your own account will be run from. If possible, look for some really good safety features -
- negative balance protection
- segregation of clients' funds
- ban on stop-hunting
- client deposit protection
- tight national control on who can be an investor and director of a brokerage
etc.
Commercial features that might be important depend on your strategy and trading style - tight spreads, fixed spreads, range of markets, news flow, chart features, platform usability, demo account availability, guaranteed stop-losses, acceptability of scalping, etc.