Maine and Nebraska award one electoral vote each by congressional district, with two electoral votes in each state going to the statewide winner. The other 48 states award them winner take all. Each state could opt to split their electoral votes based on the popular vote within their state, or by congressional district, or some other method.
The congressional district method of awarding electoral votes (currently used in Maine and Nebraska) would not help make every vote matter. In NC, for example, there are only 4 of the 13 congressional districts that would be close enough to get any attention from presidential candidates. A smaller fraction of the country’s population lives in competitive congressional districts (about 12%) than in the current battleground states (about 30%) that now get overwhelming attention , while two-thirds of the states are ignored Also, a second-place candidate could still win the White House without winning the national popular vote.