Just because a garden is small doesn't mean it can't be both beautiful and inspirational when you're designing it, as long as you avoid the most common small garden mistakes. The main thing that trips up most people is overcompensating for the small dimensions of your garden by trying to cram in more things.
Perhaps one of the best tips from garden designers is to go big with your small backyard ideas. Aim to include a stunning focal point that also has a practical function, like the most spacious outdoor dining area you can fit in. You can have fewer flowerbeds but go big on the ones you do have and layer up the plants to take the look firmly into designer territory.