Many people explain libertarianism as being socially Liberal and fiscally conservative. Because we are against both drug laws and gun laws mainly. Besides the fact that most left wing liberals support the war on drugs or at least heavily regulated drugs and most right wing conservatives aren't against most guns or at least want to still heavily regulate them.
This definition is fatally flawed though, because it completely misunderstands libertarianism. Libertarianism is more rightly defined as the belief in the nonaggression principle and property rights, no where in this is liberalism nor conservatism. Libertarians do not want low taxes to conserve government finances, they want to abolish taxation sense it is simply extortion under a new face. Libertarians do not want to legalize gay marriage to make social toleration of everyone a social norm it says the government should get out of marriage because the state, a criminal gang should not be involved in a moral institution that is high above it in the first place and force its version of that institution,(Whether it is the secular tolerant new kind of marriage or the traditional religious one) on people at the barrel of a gun.
People come up with this definition because they cannot think out of the traditional left-right spectrum, so they feel libertarianism somehow can fit into this spectrum when it simply does not. The left right spectrum is a propaganda tool to make people think statism is some how too faces completely different from each other and the great ruse keeps people distracted. The real separation is between politics and anti-politics, coercion and noncoercion.
Its important that one does not even have to be culturally liberal to be a libertarian, you could be a racist tight ass baptist that excludes everyone off of his property who isn't a racist tight ass baptist or you could be a super PC tolerant free sex hippy who lives in a commune and shares and tolerates everything and still be a libertarian, you just have to recognize the nonaggression principle and private property rights through homesteading, so you have to not force your weird ass cultural beliefs on everyone else.