As long as each connection is in the right place, you can connect up a station any way you like. The assessment is on the connection, not the sequence. What follows here is just an advisory sequence of actions, based partly on experience and partly on paranoia! Remember, you are very likely to be quite an unpopular chap if you kill the assessor's £2000 radio by switching it on in transmit at full power with no antenna connected.
1. Lay out the station equipment so that it will be comfortable to use. Remember you may spend a long time operating it.
2. Identify the key connection points on each piece of equipment.
3. Make sure the power is off. Also check that the transmitter will not start transmitting as soon as it is switched on. Be aware of the manual transmit switch (marked "Mox"). Some Morse keys have a switch which locks the transmit on, this is usually marked "tune", base microphones normally have a PTT lock too.
4. Connect the RF earth using thick cable. Normally this will connect to a screw post on the back of the transceiver and ATU, and be secured with a wing-nut and washers.
5. Connect the antenna, microphone, morse key and whatever other accessories are to be used
6. Connect the power. If the radio is powered by an external power supply unit (PSU), then ensure that you have connected it the right way round. Red on the radio to the red terminal on the PSU, and likewise for the black. Permanent and very expensive damage will be done to the radio if it is connected up the wrong way round.
7. Check all the connections you have made are correct and secure before switching on the power. Switch the mains on first, then the power supply unit, then the radio. Some power supplies can produce large voltage spikes when the mains is switched on, keeping the radio switched off while doing this protects it from possible damage.
8. Check that the RF power control is at minimum before transmitting.
