My pup is 4.5 mths old so very much a baby and I am not expecting too much from at this stage but would like to know how to teach him to keep his head up when walking on a show lead. He is a gundog.
The breed are not baited in the ring and although I have been doing this to get him to stand I would like to reduce this and not get him used to it.
When he has his show lead on he eats it! Then once we get walking its very hard to keep his nose off of the ground and I find myself having to have really pull up hard which I am worried will do his neck damage or choke him. I've tried a quick 'jerk' upwards which works briefly. He also wants to leap and bound about on it which he doesn't do on his normal collar and lead.
We do attend ringcraft but they have stopped for the summer but I just wanted to do bits of training each day for showing.

If baiting works then use bait, I expect your breed are held/stacked in the stand. 

Nothing to stop you freestanding yours for bait instead or in addition.

Plenty of breeds use bait with stacked breeds too.  After all if what you have, or you do, is less interesting of course pup will prefer to search the ground.

You can of course do classic obedience attention training 'watch me', which is usally doen using a toy or treat.

I watched them being shown on Sunday and none were given food! I don't want to look the odd one out giving food all the time or have other competitors not being happy with me.
They are stacked but I have got him to free stand once we've done a bit of walking, it only lasts a few seconds but that's good enough for at this stage. I am just starting to work on him letting me position his front feet, again few seconds before he sits down or tries to chew my hands but we are getting there.

I don't want to look the odd one out giving food all the time or have other competitors not being happy with me.

Surely what matters the most is ensuring your dog is HAPPY? What fun is going into a showring if there is no reward?

You can show your dog that there is a reward to be had, that does not mean you have to feed in the ring - just promise. And there is no reason why you can't show your dog to its best advantage, that is what good handling is about and if that means your dog gets a titbit when he has completed his assessment then so be it. (do not of course start throwing food or a toy around that is not necessary) just have a titbit in your pocket that you give or show as needed.

I don't want to look the odd one out giving food all the time or have other competitors not being happy with me.

I would do whatever I had to do so that my pup happily did what I wanted. 
The only reason for other exhibitors to be unhappy with you would be if you disturbed or distracted their dogs but for instance, throwing the food on the ground!

He's still a baby, I would much rather have a puppy who leaps and bounds about at four and a half months than a statue who will very probably be bored stiff by the time he's 6 months. I had a girl who went round with her nose glued to the grass, I used to do a "quick jerk up" which worked, for her first few shows she was also rocket propelled despite going to ringcraft weekly, she grew out of it. I would just use whatever worked for me.

I would never throw food around as I know that's unfair on the other dogs if they smell it. I will show him it and let him sniff it then reward at end. He's not a statue & can't imagine he will be, I do want him enjoying it, just didn't want him thinking or getting into habit of show lead means act like a caught fish and get sausages! Perhaps this will just fade with age and I need not be concerned.

I only do about 5mins of actual show lead walking a day as don't want him bored or dreading it. The standing is just anytime that he wants something, just like asking him to sit but instead he stands.
I didn't want to be the newbie doing something that may go against us, such as using treats if they are not normally used or alienating people that I will see at each show, I like to get on with people, but do want a happy boy in the ring.

One rule of thumb I have with my puppies when learning to move on the lead: teach them to walk before you teach them to run.
I wouldn't focus on gaiting your puppy at all right now. Just get him used to walking on the lead and reward him when he's walking beside you without his nose to the ground. Once he knows what you expect from him when walking, then start moving him faster. Short training sessions are good, but you want to be doing them multiple times a day. I tend to do 4-5 training sessions over the course of the day, each lasting no more than a few minutes each. Get what you want, then reward and end on a good note, then go back and do it again later.

I'm not sure what breed you have, but I show gundogs and always have food with me in the ring. I don't throw it and I'm not constantly feeding my dog, but my dog does work in anticipation of a potential reward. All I have to do is reach for my pocket and her tail starts going a million miles an hour. There are plenty of ways to use food in the ring without being disrespectful to other exhibitors, so why not do it if it helps your dog enjoy showing?

Thank you
I do have it my treat bag rather than pocket so he knows its there. He is getting better and at ringcraft this week he was very good and we just did short up and downs to keep him interested and focused. I then played with him with a little toy whilst back in line to keep it fun, he did find his own fun with the puppy pointer next to him!