One of my friends posted on here a while back of something he made. I think it was a highlighter marker, taken apart with airline tubing attached. The marker gave a little more siphon area than the tip of the tubing alone.
for smaller tanks.. I use airline hose... and when I want to get to the bottom of a tank... and don't want to disturb substrate or get to hard to reach places... I use long tweezers and rubberband the hose between the pincers... so i can pinpoint what i want to suck out.