Oh mate, I've been doing this for years! The main thing is pace yourself so you don't look like the sack of shit at the end of the night
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The accepted wisdom is that you don't drink kava with a full stomach but of course if you're out for a social evening then there is likely to be food involved. So what I do is to take some pre mixed kava in small bottles. Do you know the juice bottles you can get from Marks and Spencers that are about 250 ml? I usually put an instant kava in those and take 4 or 5 with me stashed in various pockets. Then when I haven't eaten for a while and it feels like a good time you can easily sneak off somewhere to neck one.
The rest of the time I will eat small amounts of food and drink something like ginger ale to settle my stomach slightly and provide some fizziness to help me burp and all goes fine. By the end of the night you're the only one with true mental clarity and you've had a good night still.