um how big is nthe plant?pics would help.,.,but i personall wait til u have at least 7-10 nodes and many side sho0ts.,u dont want to start cloning when theres not much foliage on the plant.,.but others mite say difrent.,.,so chime in fellow riu'ers
I would say that if the plant is big enough for you to take normal sized cuttings off of it (however many you take) and there's still a plant of decent size left after you do so, you may certainly proceed.
I'm a firm believer in waiting until plants are at least 6-8 weeks old from seed before taking clones. Cuttings from mature plants root better and can be put into flowering immediately after taking root.