The life of a free trader in general can suck. I'm not referring to making your monthly payments (though those suck too). A combination of running cargo, carrying passengers and wise speculation more often than not will let you turn a profit. No hard work, does pay off in Traveller despite what the LBBs advise. I refer to all the people trying to separate you from your hard earned credits.
The first obstacle to financial independence is often considered to be piracy. True to a point. Sometimes you can avoid them (the rumor mill is good for tips (buy a round in the local watering holes.) But as previous posts have stressed piracy is not limited to sociopaths in black painted cruisers randomly shooting at ships. Pirates will use their own rumor mills and spies to find out when you are carrying a juicy cargo. Take precautions.
The fact is if the skull and crossbones set has a an inside man at the port there is little you can do about it. they've spent years probably weaseling their way into a good position to pass intell to their peg-legged patrons. there are some signs that an informant is in place. If a number of ships from your departure point are attacked then there's probably a mole involved. The mole will request the pirates NOT jump ships in their home star system instead passing on the target's flight plan and following them for a jump or two. Remember the Frontier usually does not have an intelligence service set up to coordinate reports from a number of worlds. You however are fairly mobile and could do what government doesn't care to.
Sticking a spy or saboteur on your ship is good way of incapacitating a target. Be wary of people seeking working passage. Run background checks on everyone, including passengers. make sure they are who they say. Be wary of stowaways as well. There's a reasons they often pay for with their lives. Some surveillance equipment and software may pay for itself and save your life.
Your own crew can be a source of information for pirates. Believe it or not the way I hear it, some spacers occasionally partake of a taste of the grape and loosen their tongues. If you have a particularly juicy cargo do not tell anyone who doesn't need to know. Better still tell them it's something else. A cargo of video games becomes seed corn. A shipment of guns becomes construction materials. No pirate is going to go after a cargo of cinderblocks and plumbing fittings (unless they have a buyer in the construction business).
Having a functioning weapons system is often enough to discourage a pirate. A new pirate. The more established ones are going to have ships bigger than yours and bristling with lasers and missiles. This is often enough to discourage a merchant and make them surrender. They can salvage systems from ships they wreck or trap and they are probably a damn sight better shots than your guys since they put their skills to use more weapons and missiles. Nevertheless they do not want to fight when they don't have to. They have payrolls to meet, supplies and munitions to buy, and operating costs to cover.
So merchants convoy. Six or seven lasers will make even the most hardened pirate move on and seek softer targets. Law abiding ships can form up and convoy whenever and wherever they wish of course. Pirates do not have this luxury. A number of heavily armed vessels with registration anomalies will usually lead to the Navy taking a keen interest.
Note pirates will form their equivalent of a convoy. They call it a raid or blitz and it is formed to sack a large and well defended target like a colony or high port. This is a perfect storm of indisputable intelligence on a mind bogglingly valuable score that is delivered in time for the local pirate king to gather a number of ships to raid a well defended installation. But that is for another post.