Client always demands you work on projects immediately and never gives you lead time.
Overview
Letting a client run all over you is a position you never want to find yourself in. Clients must adhere to your process and be informed of realistic timelines. Most work takes longer than you think, and it's your job to educate your clients. Be proactive.
Hi <Client>,
I see how excited you are to get started with these new initiatives.
While I'm excited as well, my job is to let you know what's involved and how long each will take.
The more detail I have upfront, the less likely it is we'll have any project delays or surprises down the road.
I first need to understand the scope of what you're looking for, and when I have enough detail, I can get back to you with a realistic project timeline.
From there, you can make your own decisions based on my planning.
Let's get together and map out a timeline of the projects / deliverables you think you'll want me to work for the next <weeks / months>, so I'm sure to carve out enough time to accommodate your needs.
I believe this is an effective way to move forward.
<You>
Notes & Strategy
Being a "yes-person" to your client is no way to run a business.
It'll drive you insane and make you hate your clients.
It'll also reduce the quality of your work.
Take control by asking for details upfront, and then layout a reasonable timeframe based on your needs and schedule.
Doing this consistently will make your client respect your process
They'll be much less likely to demand everything be delivered "yesterday."
Clients act based on cues and behavior they get from you.
If you say "yes" to everything, they will expect that response all the time.