It is all in the cutting of the paper, and the folding of it. You have to cut it just big enough to wrap the present. Make the folds crisp. No wadding or stuffing of the paper at the end. And don't tape the pkg box to the paper!
Buy nice heavy paper, the cheap stuff is hard to work with. Buy some craft wire.

So measure off the width of the paper, leave an inch or two for overlap, and fold it, and center the fold in the middle of the package.

Use double sided scotch tape!

Then the end: turn the package upside down, and push the bottom edge of the paper downwards. Push it all the way to the end on both sides, and fold it so the inside piece is all the way to the end of the box, then fold down the triangle on both sides, clear to the bottom of the paper. Then pull up the top piece, and if it is longer than the side of the pkg, you have too much paper! Estimate the amount you will need to fold the other side in, and cut off any excess.

Last fold the overlap edge a little, and make a crisp fold. Tape at both ends.
the extra folds will cover any uneven cutting, and make it crisp. The double sided tape will hide the tape, you won't see it.

Do you know how to make a professional bow? It takes about 3-6 yards of wired ribbon. Just take the roll, and start making flat loops of ribbon in your hand [the size depends on how big you want the bow, obviously a six inch loop will make a 6 inch bow]. Gather them tightly in the middle, bunch each loop and hang on tight. Just keep making the flat loops off the roll of ribbon, do not cut them, just keep pulling ribbon off the spool, and turning it into the flat loops, and gathering them. About 15 loops makes a pretty big bow. Wire the loops at the bunched place fairly tightly. Then you get to fluff. Open up the loops one by one, then do it again until the bow starts looking round.

Attatch it to the package by: Leave a 3 inch piece of ribbon in your hand, and go around the box with the ribbon, and bring it to center, giv e the box a half turn, and go around the box the other way and bring it to center, give it a twist and tie it off. Take the wire from the bow, and tie it around the ribbon. The only trick is to make sure the loops are all the same size.

I Love square boxes with stripes [small stripes]. When wrapped right, the stripes all point inward and make a pattern on the end of the package. Retangular boxes are easier to wrap.

Go try Martha Stewart's website, I have seen her demonstrate how to wrap a pkg on her show, bet she has some instructions or a video on how to do that.

If you fail, go to the store and get a gift sack with a matching card, and one of those curly ribbon bows and some tissue paper. Make sure the bag is big enough to put the present in, and set the bag upright without it tipping over. Make sure everything matches. Take three sheets of tissue, and lay them out flat on the table. turn each one of them a little bit off the others, but make sure they stay centered in the same spot. Get ahold of the paper in the center, and gently shake the papers. Then stuff them down into the bag without letting go of the center. Put the gift card on, attatch the bow, and you have a pro job.