How to say it - /əʊ/ & /eə/
This is how the Queen of England says 'o'. There is a lot of movement between the /ə/ and the /uː / sounds. Other English speakers use less movement between these sounds.
Beware! The last sound is not really a /ʊ/, it is really a /uː/, but the characters in diphthongs always contain the short form of a sound, not the long form, eg. /ʊ/, not /uː/.
This sound is spelt 'o'; eg. in 'phone' /fəʊn/; 'oe'; eg. in 'toe' /təʊ/; 'ow' in 'low' /ləʊ/; or 'owe'; eg. in 'owe' /əʊ/.
This diphthong sounds like the word 'air'. Letters used to show this sound are: 'air' as in 'hair' /heə/, 'ear' as in 'bear' /beə/, 'are' as in 'care' /keə/, and 'aire' as in 'Claire' /kleə/.
To make this sound, first say /e/, then move your tongue backwards and close your mouth a bit to say /ə/.
Video of Mouth
Follow the instructions as they appear in the video.