After flying, make sure to disarm the drone while you are not operating it. This can be done by moving the left stick to the bottom left until the LEDs on the drone start flashing. At this point the propellers of the drone stop rotating. This prevents unwanted accidental takeoffs. It is also safer to disarm the drone at all times when it is on the ground; when the drone is armed, it could also react to movement when you pick it up, causing your fingers to be cut by the propellers. Regardless, always check that the drone is disarmed before handling it.
When you are done flying the drone, make sure that you disarm the drone on the drone-side as well before handling it: this can be done by pressing and holding the safety switch (on the GPS module), until it starts flashing slower. After this, it is also safer to have the batteries disconnected to prevent draining your batteries while moving the drone. Usually propellers are also taken off the drone after flying.
On-board log files are generated and stored on the SD card. These can be analysed using the tools and procedures shown here: