Tips on technique for a beginner

if you are right handed you must pivet your right foot(wich should be in the back, when you give a straight right...and try moving around more...you seem kinda stationary./..just a hint stay up bud Jay

Mal, good work, here's a couple of things to start with:

1. Check your stance.  You are pretty much square to the bag.  You really want to turn it off to a 45 degree angle to ensure your opponent doesn't have so much target.  Lead with your left.  As you are now, it's almost like you are throwing straight lefts and straight rights with no jab at all.  You also seem to switch back and forth from orthodox to southpaw.  It would be beneficial to just work on your footwork for awhile.
2. You are too close to the bag.  Every punch you throw is pushing the bag rather than getting that SNAP.  You'll no when it is the right distance because believe it or not, the bag will barely move, but there will be a loud THWACK.  Especially true when it is just your jab.  Depending on the weight of the bag (yours looks like its a 70lb?) it will swing more, but generally, you don't need to get it swinging to be effective.  Judge more by the crack/sound of your fists hitting it.
3. You start out very well with your right by your chin.  Eventually it drops off.  Really concentrate on keeping your hands up and protecting yourself.

There's a couple of things to try for now.  Pick one, perfect it, then pick another...Cheers.

1. you need to check your stance.If your unsure shadow box infront of a mirror. 2.Your Dropping your punches,after you throw bring your hand right back. Snap it back. 3.Seems like your muscling your punches, relax.think about what you are doing.

Thanks guys, all your comments make absolute sense and I can see it in the video. Much appreciated... a lot to do.

Move your side to size. Practice feinting.

Hey man you look like you gotta lot of enurance for a beginner, but i have been noticing with your right handed straight jab, dip your right leg inward it will give you more power on it.

I'm still working at not moving that bag and resisting that urge to move forward and follow through the punch to the back of the head, but it's hard. I find I'm pulling my punches instead of driving them home. Moving about is also disturbing my foundation where the power is coming from. Basically, I'm punching like a big girl and it's very frustrating, but I'm sure it will come. I just need to get that illusive 'thrack' on the bag that everyone is talking about. Again, thanks for all the advice guys. Mal