Sound Design is a task which is a part of pre-production, shooting/production, and post production. Sounds, tones,... should be planned in the pre production. It is extremely important to plan everything beforehand, and do the execution accordingly. It's important to decide beforehand what you want to achieve and improvise accordingly. I have done sound design in a few short films, and the sound design helps in adding depth to the scenes. Sound design should be layered creatively. Sound perspective is very important. Sound can liven up dead visuals. While designing sound for a short film, there was a scene which was looking absurd, I had to do ADR and design sound representing mental space, which thankfully worked and saved the scene.

Always plan your audio first, because you'll have fewer audio redundancies than video redundancies 10 times out of 10. What are the acoustics of the space? What's the backup for your backup for your backup? When a camera loses focus or a memory card dies, you can cut to a second subject or add B-roll. You really only get one shot at dialogue unless it's a scripted piece.

Audio is either driving your content consciously to the viewer e.g. a testimonial piece or narration, or it's driving subconsciously allowing the viewer to experience the environment of the content. Either way, if done poorly, the viewer will be pulled out of the content immediately. That being said, the highest quality of audio capture or design should be your first priority for your content. You've got to have clear goals on how you're going to capture that audio necessary to tell your story and keep the viewer engaged.

Different sources will affect your budget in significant ways. Depending on how many people you have in your video, the size of your sound crew and the equipment that may need to be rented can be simple or substantial. Purchasing rights to sound effects, music, and an audio editor will also take part of your budget. You may also need to book a recording space for voice overs, Foley, or ADR (Automated Dialogue Replacement).

Plan accordingly and research what you'll need in order to get the sound your content is depending on. Be aware that, unless you record it yourself, it will likely come with a licensing fee. Budget for this and make sure those usage rights cover how you or your client plan to use the content and where it lives. Never be the person who takes advantage of other creators in order to enhance your content. Play it by the book and you won't have any issues here, there are a ton of great resources.

Don't be afraid to ask someone to re-do a line if something is off. They would prefer you break the flow of the conversation than be represented in a sub-par product.

Location scouting with audio in mind can help you avoid a lot of post-production woes. How close is it to an airport, train tracks, highways, dogs, birds, and cicadas? Humans can ignore sounds in a noisy environment a lot better than microphones can.

Sound organization, similar to file structure, really comes down to "How much time do you want to save yourself?", and "How easy would you like the edit to be?". If you take the time to thoughtfully organize your audio, whether by category or source or however you see fit, it will drastically improve your efficiency on the back end of your edit. I won't even go so far as to say there's a "right" way, just structure it in a way that makes sense to you and to anyone else who might have to touch the project. Make sure all your files are able to be accessed and make sure they live in files that are easily linked to your editing software.

Most video editing software can edit in increments around 1/30th of a second, whereas most audio editing software can edit at increments of 1/48,000th of a second or better. Depending on your temperament, it might be to your advantage to either learn to use audio editing software that can work in conjunction with your video, or work with an audio editor who already has.

This is the fun part! Manipulating and transforming the samples you've recorded can be extremely rewarding and fulfilling. You can practically make any sound out of any recording, with the appropriate software and techniques. Pro tip: Try the free software PaulStretch to stretch any sound to many times its length, creating meditative drones or creepy ambiences. Stretching is just one of the tools in your arsenal of endless possibilities...

This doesn't have to be as intimidating as it might feel, but it WILL make all the difference in your content. Take a bit of time to research even the simplest of sound design techniques. Know which frequencies to remove from audio, take time to make sure your levels are consistent through the video. Even a little attention to the sound design and shaping will elevate your content above the video that just dropped in audio and rolled with it.

These days many platforms have loudness standards that need to be met. Do research to see what your publishing platform requires or recommends. Well equipped audio engineers (or re-recording mixers) should have the tools necessary to meet the standards of your desired platform while creating the sonic experience you and your audience desire.

Some things I consider and try to remember are: The quality of the equipment.. you might have to go with the brand names you can trust if the budget allows or spend more time in post production. Also, .WAV files/ high quality files allow more to be done in post while maintaining the overall sound quality. As well as having output and sound monitoring equipment to give accurate feedback.