To help you be seen at night, wrap around your ankles a pair of reflective straps whose ends hold together using Velcro. An added benefit is that, if you are wearing long pants, these keep your cuffs away from the dirty bike parts. Reflective straps can be found at a bike shop or sporting goods store.
To make your hand signals more noticeable, it helps to have wrist bands similar to those ankle straps. Also useful is reflective material on your gloves and jacket sleeves.
In addition, wearing bright green or yellow clothing is helpful anytime. Orange and red are eye-catching in bright daylight, but not in low light. Also, athletic clothing with reflective material is a nice choice.
Perhaps you prefer to wear normal looking clothing without those bright colors, but you don't want to change clothes on arrival at your destination. If so, restrict the bright colors to outerwear that you can easily take off and hide, like a thin jacket.