As a left handed adult, also a Guide leader used to dealing with both right and left handed children, these are the tips I have:
Don't force a preference, either way. They might not settle for years, so ask childcarers or teachers not to too.
Make sure any child (left or right) has plenty of space when writing, drawing or painting. With the left hander, find out how to position the paper at an angle (see already posted link) and help them to do so.
Remind carers and school teachers about this (space and angle) and remind the child too, as they get older they can insist for themselves. Putting a righty to the left of a lefty is asking for elbow fights.
Be aware, when it comes to tool use as they grow up, that scissors, peelers, sharpeners, serrated knives and can openers are usually "handed" and can be harder and sometimes more dangerous to use. Decide whether you want to get the lefty tool, ambidextrous (where possible) or teach them to be aware of and use righty ones correctly and safely... You can also get pens and pencils which support good pencil grip - lefties often have very awkward looking grips and get finger cramps easily.
Ambidextrous can openers are easy to use but leave a sharp edge, ambidextrous peelers I like a lot, sharpeners I've never even bothered with a righty one. My mother made sure I could use right handed scissors in my right hand (and left in my left) because there are a lot of times when you just don't have access to lefty scissors. My righty Guides used to grab the lefty scissors first and when I asked they said that the lefty scissors at school were usually the non-blunt ones because the righty ones got used first. Make sure the scissors you have either way are good enough for the job. Note that so called ambidextrous scissors merely have unshaped handles and are not actually ambidextrous - the handedness of scissors is decided by the way the blades cross. In the correct hand, the hand naturally presses the blades together when cutting - in the wrong hand, it pushes them apart. Serrated knives are, well, difficult (again see link). I learned how to use righty ones in my left hand, but I'm not convinced it is that good an idea as wedges of bread were rife for years. On the other hand, my lefty sharp knives are kept hidden from my husband.
Kettles on the round bases are good - means either of us can use them.