Minimalism is a lot more than constant repetition of a single gesture. Broadly speaking, any time we purposefully restrict the means of a composition, we have engaged in a kind of minimalism.
One way to approach minimalism is in the realm of pitch.
Using only four pitch classes (you may choose which), compose a piece for orchestra. You may not use transformations on your set of pitch classes. You must find ways to sustain our interest by taking advantage of your relative freedom in the other musical dimensions (rhythm, form, dynamics, timbre, etc).