Stars between 0.8 to 8Msun are the most common evolved stars in galaxies. In their evolved phases these stars contribute significant gas and dust to galaxies, and contribute to galactic chemical evolution. The richest nucleosynthesis occurs when the stars are on the AGB, where elements such as C, F and elements heavier than iron are produced in their cores, and mixed to the stellar surface by convection. Intense mass-loss then expels this material into the interstellar medium, leaving the white dwarf remnant. The integrated contribution of low and intermediate-mass stars is usually determined by calculating theoretical stellar models of an entire population but these calculations are subject to a number of uncertainties. In particular in recent years it has become apparent that many AGB stars and planetary nebulae are shaped by interaction with a companion. Second, the minimum mass of stars that produce C and heavy elements is still very uncertain. This uncertainty is important for chemical evolution since the lowest mass is usually the most numerous. In this talk I discuss recent efforts to improve our understanding of how low and intermediate-mass stars contribute to galaxies. This includes examining the role of a companion on populations of stars, and using observations to better constrain mass loss, rotation and convective mixing.