By the time babies are around 3-4 months, their window of wakefulness is about two hours, the latter hour being one of when baby wants to be held.
Hence, if you want to get things done, that first hour is when you have the most flexibility. This is the hour when after nursing, you are able to get yourself ready, cook, eat, vacuum, clean, fold laundry, work, or write emails while baby plays on a play mat or in the swing or bouncy chair.
At about the second hour, she likes to to be held. This is when I hold her to practice standing and/or hold her with in my lap and play piano and sing. We also walk around the house and pick up/tidy, load laundry or switch to dryer, put dishes away or read to my other children. I have even vacuumed while holding her too. She enjoys the noise and the movement. Women have great hips where baby can sit on while you multitask. :)
My motto is: try not to always do things FOR the baby but do things WITH the baby. Incorporate baby into your life as much as possible, around her sleep and nursing schedule.
Having said that, most of my cooking is done while she is sleeping. I may hold her while washing fruits or vegetables, as she likes the sound of water and watching the process. However, with all of the chopping and heat work, baby needs to be safely away.