Straps must be in good condition - not worn or frayed
They must be sufficiently rated to the weight of the load
Lashing straps should be used to secure loads rather than ropes unless they are demonstrably rated
To follow best practice, all loose loads should be sheeted to prevent loads from bouncing or blowing out, whatever the type of trailer you use.
You must check your load is secure every time you take your trailer out whether for a short or long journey