Clocks
Definitely need a good timer. In my early days, the simplest was to buy a Casio digital watch (about a fiver - probably similar today) take the wristband off, and velcro it to the centre of the yoke. Perfect for brakes off and on, and also had a timer function. Cheap!
More recently, a digital kitchen timer clipped to the side of the screen using a phone holder suction device (bought on motorway services) is larger and has two timer devices. Boots used to do a really good one, but now you need to surf to find one. Current one I use is "Brannan dual timer and clock". Same as old Boots.........