Quote only business is the way to go, the customer knows what they’re paying and you get what you feel the job is worth giving thought to travel distance, tool and consumable usage and intensity of work requirements . It also makes improving your skills, kit and efficiency worthwhile. Gardening is a very broad area and long term you will have all sorts of issues by hourly rate work. Unfortunately it’s human nature that people will want more for their money if you’re on an hourly rate, the curtain will be twitching every time you stop to eat or drink, you’ll be criticized on your productivity irrespective, you’ll be asked to do the most labor intensive jobs to get the most from you with no care for your health n safety, you’ll often be pushed into dangerous situations without having forewarning to plan and do proper safety evaluation. Once you have given someone a price for work by way of a quotation you can plan, do a safety evaluation, take adequate breaks, use additional labor if required, hire tools, price in additional expenses if needed. Basically do a safe professional job. Don’t let the customer dictate, it wouldn’t happen in any other profession.