The jurisdiction you select will be the source of law by which your trust operates. For e.g. if you create your trust in NSW, you will be subject to the law, including statute, rules and regulations of NSW. In terms of a dispute arising within the trust or in close connection to it, the courts of NSW will have jurisdiction to hear your matter.
In addition, your trust will be liable to pay the taxes expected under state law. Stamp duty is one such example. Certain states and territories require your trust deed to be stamped and stamp duty to be paid. In NSW, trusts must be stamped within 3 months of execution and the stamp duty is $500. Yet in the ACT, QLD, SA and WA trusts do not need to be stamped and are not subject to stamp duty.