Don't get double-taxed on income, specifically. You may still get double-taxed on investments, property, wealth, etc depending on which pair of countries

When I moved from country A to country B, I shipped quite a lot of stuff (books, board games, etc) that was too heavy to take on the airplane and which I could live without for a month or two. Country B did not charge me customs duties on my books, but did charge me customs duties on my board games; I think they must have looked at how many I had and thought "There's no way this is personal possessions, he's bringing this into the country to sell them." I decided not to argue with them about it, so I got double-taxed on some of my property (sales tax on it in country A when I bought those games, then customs duties in country B years later).

P.S. My collection of board games is not particularly impressive for a board gamer: it's in the double digits, but not in the triple digits. I know some board gamers with far more games than I have.