Where you decide to mount the tracker is up to you and your use case. However, please do not fully surround the tracker with metal as it blocks the signals.
Below are some recommendations for best performance, if none of the suggestions work well for you, get in touch with details of your use case.
People: a bag, shoes, outside pocket, keys, lanyard
Assets: face the device upwards with a clear line of sight to the sky
Vehicle: glove compartment, under the seat, underside of the vehicle (magnetic LightBug Pro)