Pat his back very gently, with firm movements, until he gradually calms down and stops crying. Massage his forehead, between his eyes, and behind his ears, with steady circular motions, to calm him down and give him a feeling of relaxation, and then calmness and sleep.
Look into his eyes directly, as this method is proven to keep the baby calm, and you can sing to him as well, or repeat some quiet steady sounds
Put him in his stroller and go out with him for a quick walk around the house or in a nearby park, and if the time is not right, maybe a few minutes on the balcony will improve his mood.
Try feeding your baby in a different position or giving him a pacifier to suck on for a bit, the sucking process in general helps soothe babies and makes them feel relaxed
