I use `auto` when the type is obvious or doesn't really matter, and I seldom create aliases for types.

I feel like having verbose type names at function boundaries and using `auto` for dependent types is the sweet spot. I'll often avoid `auto` when referring to a class data member, so the reader doesn't have to refer to the definition.

    void foo(const std::multimap<double, Order>& sells) {
        for (const auto& [price, order] : sells) {
            // ...
        }
    }

    void foo(const OrderBook& book) {
        const std::multimap<double, Order>& sells = book.sells;
        for (const auto& [price, order] : sells) {
            // ...
        }
    }

    auto iter = sells.begin();
    std::multimap<double, Order>::const_iterator iter = sells.begin();