My system probably isn't for you but maybe it will help someone else...
Here's my one-woman-show $10 system...I'm cheap and I like to keep things simple.
I calculated my hourly rate by using the Signcraft worksheet and recheck after taxes are done as I have all the overhead info at my fingertips for the year.
I use Wave (free and simple) for estimates and invoices, no option for inventory so I track it on an Excel spreadsheet with formulas that calculate linear yard, feet, inches for vinyl and $Start 2019 $End 2019. Both are super easy and fast - no bells and whistles just exactly the information needed for tax purposes!
I use my desktop as a production scheduler. I had to dish out $10 for "Fences" which allows you to organize your desktop with large folders that your icons stick in - my categories are Estimate, Artwork, Proof Out, On Order, In Production, On Hold, Invoicing.
Inventory - as I purchase things I print the vendor invoice out...every vendor invoice gets a PO# which is a sticker. It goes on a clipboard until it arrives. Upon arrival items get a barcode sticker with a 4 digit number on it. There is another sticker I put with the vinyl which includes color, brand, price per linear inch, etc for reference.The barcode number gets written on the vendor invoice next to the item. This info is entered into Excel as inventory. As I use the vinyl for jobs I write the barcode # on my job ticket and the price per linear inch so i can calculate exactly how much each job costs. If vinyl fails 6 months down the road I can track exactly which roll and which invoice it came from. Every job gets a job # sticker on the job ticket- everything can be cross referenced and found super quickly if needed. Job ticket tracks labor, costs, etc. I consider entering this info into Excel but I'm too lazy. My spreadsheet contains date, PO, barcode #, vendor, brand, type, color, description, price, qty, width, yards - then calculates the following" linear feet, inches, square inches, price per yard, foot, linear inch, square inch, 2019 Start, 2019 End. I use the same sheet for substrates just don't fill in everything. The main priority is total $ 2019 Start and 2019 End, everything else is just extra - I can quickly filter to look for something or mark something as "out of inventory". I don't need 3/4 of the calculations but I just really love making spreadsheets. Every Monday I take the vendor invoices and go through Wave to cross reference each transaction and mark them "completed". I take photos of any store receipts and upload into Wave using the phone app. I scan all my vendor invoices into OneDrive and label them "306 Fellers" (PO#/vendor) and toss the paper copy. Job tickets get filed in manilla folders.
That's my $10 system LOL
Of course all of this can be done in Quickbooks or Estimate which I've used in the past but stickers and spreadsheets are more fun! I've been doing my own taxes for about 10 years but had to hire an accountant this year due to divorce and he was impressed with my 2 sheets of paper for my business. One report from Wave and one screen clipping from Excel...done!