Theory of phonetics

[о]is closer than [L] and more rounded.
You are to give a shade of [a]to the beginning of the vowel [L], and a shade of [у] to the end of the vowel to avoid mispronunciation.

[V] back advanced high-broad slightly rounded short and lax. It is pronounced with the bulk of the tongue in the back part of the mouth cavity, but somewhat advanced. The back of the tongue is raised in the direction of the front part of the soft palate, higher than for [L]. The lips are slightly rounded.

[у] is more back. It is pronounced with the lips far more rounded and protruded than for [V]. [V] is pronounced somewhat medium between [у] and [ы]. [V] \/ [у] [ы]

[H] back high-narrow diphthongized rounded long and tense. It is pronounced with the bulk of the tongue retracted more than for [V]. The back of the tongue is raised in the direction of the soft palate higher than for [V], but not so high to cause audible friction. It is diphthongized because during the pronunciation of [H] the tongue may move from a more advanced and open position to a closer and more retracted position. In this case the tenseness of the vowel gradually increases towards the end. At the beginning of [H] the lips are fairly rounded. Towards the end they are still more rounded. The opening between the jaws is narrower than for [V].