Lobster is an expensive ingredient and requires careful cooking for the best results. Cooking the lobster sous vide ensures a soft texture and locks in the flavour. Only buy lobsters from reputable fishmongers and check that they are alive before buying.
For a richer flavour, add butter to the bag with the lobster instead of oil, or better yet use a beurre noisette – the nutty flavour will complement the lobster perfectly.
You could also try adding a little shellfish stock to the bag for an extra flavour boost, or a glug of brandy will give an interesting finish.
Another flavour that would work well in the bag with the lobster is vanilla; it's an expensive addition but the sweetness brings out an extra dimension in the lobster.