You can prune off the tips of the branches by cutting at the point just above the leaf nodes (where a leaf emerges from the main stem). These tolerate pruning well and even can be cut back entirely to a bare stem. New shoots will develop from latent buds in the trunk. It is up to you how much you want to take off to manage the overall size and shape.

For Schefflera, you can use a soil-based potting mix that contains peat moss and perlite. Transplanting is recommended in the spring. Keep the soil moist from spring to autumn. Reduce watering in the winter during the plant's rest period.

ckc