Depending on where you set up your still life, and the objects you choose, the perspective can be straightforward or more complex. Mundane objects can be transformed by a setting, and mundane settings can be transformed by your choice of viewpoint.
Decide whether you're going to be painting standing up or sitting down, and then arrange the still life objects to match that. Do you want to be looking down on the objects? Will they be straight ahead, at eye level, or above you? As adults, the viewpoint we're most accustomed to seeing is downwards, down onto a table top.
Avoid Kissing Objects
Don't place still life items so they're kissing. One of the most distracting things you can do in a composition is to kiss, or have items just touching each other rather than having a definite space between them or a definite overlap. The viewer's eye doesn't know whether to move from one object to the other, and gets distracted deciding whether or not there is indeed a sliver of a gap between them or not.
Also, remember that the point of view that you set for your still life may well influence how the final painting is hung and where you hang it for exhibition. If you are looking down on the still life in terms of the composition, it may end up looking strange if it's hung up high on a wall, with the horizon line of the painting a lot higher than the eye level of the observer. Extreme variations can give a painting tension and impact, but may just put the observer off.