I'd rather not have to put my mouth on the hose
Hey man, if you haven't sucked in a mouthful of tank water, then you can't call yourself a true aquarium lover!!!
But seriously, if you're siphoning into a bucket, then you can get the entire hose full (if it's a short one) but submerging it in the water and then putting your thumb over the end and lifting it out, then put it in the bucket and let go, gravity will take over.
Also as far as the sucking the hose part, what I do (to clean SW sumps, which are usually just a few inches off the ground) it suck in the hose and get enough water in it (about 1/2 to 3/4 of the way) and then lower the end of the hose down so the end is near the water level and let off and on until it gets to the end, then put it in the bucket.
Also, if your tank is full (sump is 1/2 full) then you could put one end in the water, suck really hard on the other end briefly and then point that end back into the tank, momentum will carry the water to the end of the hose, then thumb it and move it.
Hope this helps. But there's just no substitute for sucking.