To get bigger leaves you need more light and humidity. Make your home as close to greenhouse conditions as you can. Think very bright ( although they are low light tolerant they will grow bigger in brighter conditions), very warm, very wet. Not the most comfortable so get as close as you want and expect less glorious ness. They will bloom all year round with sufficient light. If they get too tall, just cut them a little lower than you want them to be and they'll sprout a couple new shoots right below that point. You can plant the cuttings directly into potting soil without rooting them in water first. As far as fertilizer goes, you can use any houseplant food you want — they can't read. Something with more nitrogen ( the first # on the label) will encourage more leaf and stem growth.
They are one of the easiest plants to grow and with a little effort they will look better.
Happy plant parenting!
