Those crank operated or electric tabletop sharpeners are great. For a portable sharpener, my personal favourite is the KUM long point automatic two-stage sharpe

Those crank operated or electric tabletop sharpeners are great. For a portable sharpener, my personal favourite is the KUM long point automatic two-stage sharpener. The way it works is that it first sharpens the wood leaving a round core and then points the lead inside. The longer point stays pointy a little longer than standard. The only downside is it's a little hungry and uses up pencils a little quicker than normal. Jetpens sells them in the US and Cult Pens in the UK. I can highly recommend both. Good pencils help too. I tend to prefer German and Japanese brands like Staedtler, Stabilo, Mitsu-Bishi, and Tombow.