从来不

从 = 人 : Mnemonic symbol: 从 looks like the legs of a rubber chicken. Two Neanderthal Men (人) are playing a game with Kitty Cat (cu) in the engine's kitchen ((e)ng2). They stand in a line and let Kitty Cat pass through (从) the tunnel formed by their legs by teasing her with a rubber chicken (从).

來 = 从 + 木 : Mnemonic symbol: mailwoman. Sir Lancelot (l) is visiting the mailwoman (來) in the airplane's kitchen (ai2). As a gift, he brought a Christmas tree (木) decorated with rubber chicken (从).

来 = 丷 + 未 : Mnemonic symbol: mailwoman. Lancelot (l) is super happy that his inflatable crocodile (丷) and live size Ai Weiwei (未) puppet finally arrived (来). The mailwoman (来) delivered them straight to the kitchen of the airplane (ai2).

不 = 丆 + 卜 : Bruno Bear (bu) is setting up a wind wheel (丆) with a voodoo staff (卜) in the space station's bathroom (Ø4). He also puts a "forbidden" sign (mnemonic symbol for 不) on it, to make clear that it may not (不) be stopped.