It depends on many factors in one's soul including overall sensitivity, past life progress or mental blocks in the mind. I'm sure other members can go deeper into the many factors that have to do with this.
But the main point is that you shouldn't worry about how fast or how strong you feel the chakras opening or activating. While it's good to focus and analyze your spiritual development, this should never get to the point of "worrying."
Just follow the meditations on The Jos website as there are many mantras, runes, breathing techniques and points of focus involving the chakras that as long as you keep working on them every day, you are bound to at the very least activate them and be able to feel them.
Obvious tips are to make sure you're as focused as you can when you're meditating and when vibrating any mantras and runes, feel free to work with a pitch and tone that feels best to you.
How you will feel the effects of this meditation depends on how much time you have spent developing in your previous incarnations (also, it should be added that each of us is different and may feel the effects of meditation in our own way).