Everyone wants DIY projects to tackle. Insulation is no different.  More and more people are installing insulation without the use of a profession. However, choosing the best DIY insulations depends on the area you need to insulate (walls, attic, floors), your budget, and needs such as thermal resistance, soundproofing, or moisture control. I have listed a few DIY insulation types and the reasons recommended:

1. Fiberglass Batt Insulation: When the average person thinks of insulation, they are probably thinking of Fiberglass Insulation. It is affordable and one of the easy to insulation DIY types to tackle install. It’s suitable for insulating walls, floors, and ceilings. Fiberglass batts come in pre-cut panels and should fit standard spaces between wall studs and ceiling; therefore, they are a good choice for DIY projects.
2. Cellulose Insulation: Though this was listed as an insulation DIY project, I’m skeptical whether the average person wants to tackle this project. You must rent an insulation blower to install this loose-fill cellulose insulation. It does have a higher R-value per inch than fiberglass, but it is more expensive, and again, renting a blower made more than what you want to bite off.
3. Spray Foam Insulation: Although pricier than fiberglass, it is an excellent air sealer because it seals gaps and cracks. You can get DIY foam insulation kits if you have a smaller project; however, it may also be a more involved project because you get protective gear.  
4. Rigid Foam Board Insulation: I heard some contradicting remarks regarding the ease of using this product. It is primarily good for insulating basements, crawl spaces, and attic floors. It is a little more expensive than fiberglass. Supposedly, it can be cut to fit various spaces and installed with adhesive or fasteners.
5. Reflective Insulation and Radiant Barriers: Reflective insulation is best used in attics in hot climates because it reflects heat away. It’s easy to install by stapling to members, and it reduces cooling expenses because it reflects radiant heat away instead of absorbing it.
6. Mineral Wool Insulation: Though it is not often requested, mineral wool has a higher R-value than fiberglass insulation because it is denser. Therefore it costs a little more.   It is usually called rock wool or slag wool. Mineral wool insulation offers excellent fire resistance and soundproofing properties. It comes in batts and loose-fill forms and can be used in multiple places, such as walls, attics, and basements. Mineral wool is denser than fiberglass, providing better sound insulation and a higher R-value for thermal resistance. If purchased in rolls, it would be a good option as an insulation DIY project.

Summation: DIY insulation types are multiple for metal building and pole barn insulation types. Your selection will be affected by the purpose of the insulation, such as thermal protection, moisture control, radiant barrier, or soundproofing. Your budget and the particular space (walls, attic, floors) being insulated will also affect your choice. When you have a doubt, please consult an insulation professional.