A method of assembling a tubular simulated cigarette is disclosed. In order to be a successful commercial product, it is important that the simulated cigarette can be assembled simply in a manner which is suitable for mass production. The method comprises providing an elongate hollow housing () having an inhaling end (2) and a refill end (3); inserting an outlet valve tube (7), a dip tube (20) and a support (30 from the refill end so that the support supports the proximal end of the dip tube in the housing; inserting a refill valve (10) into the refill end and fixing it in place to form a composition reservoir (4) with the dip tube (20) placing the reservoir in fluid communication with an outlet orifice when the outlet valve tube (7) is open; inserting a valve element (6) into a recess in the side of the housing so that the valve element is positioned to selectively close the outlet valve tube (7); inserting a breath operated valve actuation mechanism (5, 8, 9) laterally into the recess; and applying a cover to the recess.