Engine bay cleaning may be a bit controversial in some circles but here is a little before and after of my engine bay. The steps I took are as follows:
Remove engine cover, cover intake filters(if aftermarket) with bags, and take the negative terminal off of battery. Keep your hatch open at this point.
Lightly spray engine bay with water using the shower setting. Then foam the hood and engine bay with car wash soap using a hand pump foamer. Let that sit for a minute or two and rinse down. Do not saturate the hood heat shield. Note: if you don’t have a hand pump sprayer, a regular spray bottle will suffice.
Next, spray a degreaser on the entire engine bay, spraying more on areas that are heavily soiled. My heavily soiled areas were the driver side turbo and the oil filter housing. Let the degreaser sit for 3-5 minutes depending on outside temperature. During this time, use a small detail brush to get the nooks and crannies. Rinse with the shower setting.
Lastly, dry your engine bay using a leaf blower. If you don’t have a leaf blower, you will need to resort to using a towel. Once it is dry, remove bags from the air filters and put the negative terminal back on to start the vehicle. Let the vehicle warm up to let the water evaporate especially if you don’t have access to a leave blower.
If you guys have any questions or tips in addition to this, drop them in the comments! I’ll put the products I used in the comments.