That is a good point, is he really conservative in his personal outlook and behaviour, you do get a broad church of opinion in the conservative movement, and you couldn't really say he was a liberal. The wikipedia definition of 'american conservatism' seems pretty accurate and probably fits Trump:
American conservatism is a broad system of political beliefs in the United States that is characterized by respect for American traditions, support for Judeo-Christian values, economic liberalism, anti-communism and a defense of Western culture. Liberty within the bounds of conformity to conservatism is a core value, with a particular emphasis on strengthening the free market, limiting the size and scope of government and opposition to high taxes and government or labor union encroachment on the entrepreneur.
The major conservative party in the United States is the Republican Party, also known as the GOP (Grand Old Party). American conservatives consider individual liberty, as long as it conforms to conservative values, small government, deregulation of the government, economic liberalism, and free trade, as the fundamental traits of democracy, which contrasts with modern American liberals, who generally place a greater value on social equality and social justice.
How the liberals intend to obtain social justice and equality not only for the current americans but also anyone else who wants to move there is the sticking point for many on the conservative side of the fence, how do you achieve these things without massive interference, nannying and big govt, and who picks up the bill. Note it says 'modern', trump would've fitted into the 80's democratic party without too much fuss, and I think he was a member of the party at some point in the past and certainly donated to them.
Also from wikipedia on that point
In 1987, Trump spent $94,801 to place full-page advertisements in three major newspapers, proclaiming "America should stop paying to defend countries that can afford to defend themselves." The advertisements also advocated for "reducing the budget deficit, working for peace in Central America, and speeding up nuclear disarmament negotiations with the Soviet Union". After rumors of a presidential run, Trump was invited by then U.S. senator John Kerry (Democrat from Massachusetts), House speaker Jim Wright of Texas, and Arkansas congressman Beryl Anthony Jr. to host a fundraising dinner for Democratic congressional candidates and to switch parties. Anthony told The New York Times that "the message Trump has been preaching is a Democratic message."