Winston66, Here
This is what I have found that is applicable to my trailers. I have built and use three of them
Tow ball weight , Anywhere between 15 to 30 Kgs seems ok.
Tire pressure , my trailers run 450/12 4 ply with an all laden weight of up to 205 Kg and std leaf springs, I find that a pressure of around 25 Lps is plenty, Pour some water on a flat concrete surface and then run the trailer over it and the the dry surface next to it and observe the tire track pattern to see the contact surface pattern of the tires, this will give you some idea as to weather the tires are either over or under inflated. The biggest indicator in my opinion is to weather the trailer bounces excessively at speed and weather the tires appear to run hot after about 50 klms or so.
The hitch. Get a hitch that will swivel through the full 360 degree rotation, This is purely a safety thing.
Draw bar length, If you do not want the tail to wag the dog , make sure that the trailer draw bar is between one point eight , to two times the tire track width of the trailer, measured from the trailer axle to the tow hitch, and the track width from the centers of the trailer tires.
Loading, Put heavy items down low over the axle and secure them with straps or a net, just use your commonsense,
Towing speed, Do no be in a hurry but travell at a speed that you are comfortable with,
Leave plenty of distance around yourself for maneuvering, and stopping,The extra mass has to be allowed for.
If I hit a rough patch of road , or even a very windy patch or heavy gust, I do not try to control the bike with am iron grip, instead I just let the bike move around under me and it will sort itself out very easily, this can take a little bit of practice.
Leave plenty of curb side room when cornering eetc,as the extra width of the trailer needs an extra two to three feet of clearance.
Please keep in mind that the more stowage space that you have , the more stuff you will want to take, and most of that will probably not be needed anyway, The easiest and most useful stuff to take as my dad used to tell me is MONEY, it packs flat , takes up very little room in the pocket and anyone will accept it for services rended .
One could go on and on, but in trailering , like in most things in this life I have found that the KISS principle is a good and practical rule to follow.
Happy camping and touring,
Cheers,
Winston66, Northampton, Western Australia