You begin by visualizing the word with its English meaning and then use substitute words to form an association. For example:
The Spanish word for boat is barco. You could visualize a boat with a dog standing on the bow barking with lots of O’s coming out of its mouth.It can be challenging to find substitute words but once you create a vivid mental picture it will be much easier to relate the foreign word to its English meaning and vice versa.
The French word for house is maison. You might picture a man building a brick house. He is a mason.
The German word for window is fenster. Imagine a window being attacked by a fencer in full costume.
The Italian word for hat is cappello. For this you could visualize a person wearing a baseball cap made of Jell-O. Imagine it being colorful and jiggling. Cap and Jell-O will trigger the memory.