Foolproof balcony gardening

I have a friend who lives in a midlands city centre apartment with a balcony. She would like to grow some plants but isn't particularly greenfingered and sometimes needs reminding to water things. I'm not sure which direction the balcony faces but it was in sun in the afternoon this weekend.

Has anyone got any ideas as to what could be planted up to add some interest to her balcony that's hardy and easy to care for? I was thinking maybe some succulents? She was also thinking she might like to grow some things to use in the kitchen, such as herbs.

Thanks,

abbiecadabra