I'll be amazed if anyone can offer a solution to this small but niggly problem, still you never know, so here goes:
Since the earliest days, my son now aged 7, will accidently tip over any drinking container in his vacinity. When he was 2 - 4 we accepted this as part of normal exhuberent toddler behaviour. But at 7 he's still doing it. Over the years, as appropriate, we have tied all sort of approaches - telling him off, sending him to his room, treating it as a pure accident and cleaning up the mess ourselves, getting son to clean up the mess. Even joking about it with him in a resigned sort of way. He gets upset with himself, too. He looks so guity when it happens. Now we rely on damage limitation: putting cups way out of easy reach - so if he's sitting on the sofa eating a sandwich, his drink is on the mantle piece.
On average he must spill 1 cup a day - as a toddler it was about 3.
He seems to have a fascination for liquid in containers. He loves pouring different fruit jiuces into one glass to make a 'cocktail'. Usually he stops before the glass overflows - but then always spills juice from the carton. I've even caught him upending a full glass of milk because he thought he saw something interesting in on the bottom of the glass. At 7 years I can't stop him getting drinks for himself - he likes cooking too (nothing hot). He's a pretty mean sandwich-maker and his coordination regarding bike riding, ball throwing etc is very good.
Cups, though, are his downfall. Is this normal behavour?