There are a few different ways of answering your question. The main issue that I see with owners that are walking their dogs are the following:
1) Your dog has not learned the 4 basic commands. The main command a dog should know for the sake of walking is "come when called". So, if the dog does get distracted, he will come to you.
2) They do not know the heel position. This does not mean that the dog has to walk by your side the entire time, but the structure you as the owner have, the more confident you will feel. By you feeling more confident and feeling better, the dog will feel better.
3) You are stressed before you even walk out of the door for your walk. This leads to poor body posture, shallow breathing, negative energy, an unecssarily tight leash, and eventually frustration that is normally taken out on the dog or on to yourself. Before you go out on your walk. Take a moment, take 3 deep breaths, think of something positive and enjoy having a dog. A lot of people who want dogs, do not have them for several reasons. So feel blessed, and enjoy your walk.
4) Body language: You should feel relaxed during your walks. This is does not just happen over night (although in some cases it does). Knees slighly bent, shoulders back, chin up.
4) While you walk, you should walk with intention. This means act like you are going some place with purpose. This has nothing to do with speed, but everything to do with being calm, assertive and yet knowing that you have a destination that you want to reach.
5) Although, we refer to this as "your walk" we also want the dog to have a chance to smell around. So, please be a bit flexible and allow the dog to smell around. They are curious creatures and some have been indoors all day. Let them roll around in the grass. Enjoy yourself.
6) Your leash is way too tight. There are situations where a dog will need to have a leash that is tight, especially if the dog has not been taught how to walk correctly. This is not the dog's fault.