Sending parcels from the UK (Muscat)

I'm moving out to live in Muscat next week.
Although my baggage allowance is 50kg (paying for extra) I'm finding that difficult to get under that, even after unpacking what seems a lot of clothes and shoes several times. I'm not even bringing furniture or any comforts of home. Another 10kg should do it -maybe :)

Has anyone sent a parcel out from the UK?
Any company you can recommend?
What's the best way to send things - boxes
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