If your DALL-E 2 images aren't turning out how you'd like there are a few things you could bear in mind. Ensure your prompt is a detailed as possible – including detail about the background if that's important. Specify the style of art you want if you're going for an artistic style, or specify camera angles, lighting details, focal distance and even the specific camera if you're aiming for a photographic style.
DALL-E 2 struggles with requests for images of multiple subjects, so if possible keep it to one subject. That can be limiting, but if you want to create images with multiple subjects, you could try creating separate images and then editing them together. Remember that you can edit images in Dall-E 2 or alternatively export them to edit in the best photo editing software.