Some things are best left to the professionals.
Cover art – this is the very first impression that you have with complete strangers. A cover will either say, “I didn’t put any money into this, don’t bother” or “I created this book with excellence and I value your time.” The latter will get a click in Amazon or get someone to pick up your book in a store. I highly recommend KL Cooper with UnderCover Press.
Editor – No matter how many times you go through your book, no matter how many friends read through it, no matter how many times your spouse goes through it – unless they get paid to be an editor, don’t stop with them. Shell out the cash and get a professional to look at your work. I highly recommend at Destiny Writers.
Formatter – If you are good with MS Word or Adobe InDesign and you have A LOT of time, you can do this yourself. It took me about three months to do my 318 page paperback and another month to do my eBook. Formatting a paperback involves a lot more work than an eBook.
Marketer – When considering hiring someone else to market your book, be sure to measure the cost. This can turn into a dark hole fast.
Beware when hiring from Fiverr.com. Most people who advertise there are across the globe from the US. The time difference, language, and war outbreaks can make it hard to work with them. Also, you will most likely pay more than what is advertised.
I also suggest finding author groups on social media that can answer your questions and be a wealth of information. Whatever or whoever you use, be sure to get good references first (don’t be afraid to ask for them).