For PC Corel Draw is one of the best options and iDraw for Mac. Both allow drawing almost everything and generate vectorial graphs in different formats.
I use Inkscape. It is vector-based and suits me for outline drawings and schemes. Check this figure (in attachment) I made and published using solely Inkscape.
Source: Article Proton-transfer-reaction time-of-flight mass spectrometry (P...
A couple weeks ago I read about this site on Twitter, is a free platform very similar to biorender. I haven't had the opportunity to try it but seems very friendly & useful.
Thank you all for your suggestions. Indeed there are lot of options. I did not know biorender.com or bioicons.com. For free images I usually use vectorial images of Pixabay https://pixabay.com/ or using icons from the nounproject https://thenounproject.com/
Inkscape and biorender are good options but if you are on a budget then downloading free png and vectors and using it in powerpoint can get the job done.
You can use xmind app (https://www.edrawsoft.com/ad/mindmaster/index-1.html?gclid=CjwKCAjw87SHBhBiEiwAukSeUTjUI5Wt9iijS_D-zKUXkvYwkumAYcdPqK9PbcG7B4aTwb0RYjtjwRoCluQQAvD_BwE) , free version has limitations, paid version is excellent and so easy to use. You can use Cell illustrator site (www.cellillustrator.com)
too if you want to draw any pathway within cell. According to your need you can choose.
You could use R within rstudio environment, I suggest you ggplot2 to create and design your figures. The software is completely free and available for Mac and Windows
I use and recommend an online software named Mind the Graph. It has a gallery with many illustrations, and you can request a customized illustration with you do not find what you need. Here is the link.
Get your scientific and technical content translated into a stunning scientific illustration that is perfect for prestigious publications. Check out this website:
https://unitechlink.com/scientific-illustrations/
The price is very affordable (with discounts for students).