Whole Foods has a pretty affordable large bottle of fish oil caps that are lemon flavored, no fishy burps. They have specified levels of the omegas EPA and DHA (the ones that are important) on the label so if you are trying to hit a specific target you know how much to take.
For fiber you should be able to find ground flax seeds. You can scoop these over oatmeal or cereal if that's your thing; I have found that they're actually pretty tasty mixed into guacamole (they give it a unique texture). You can also get creative and hide them in lasagna or meat loaf, or use them in breading mixture for fried chicken, etc. They're loaded with soluble fiber, the kind that helps lower cholesterol.
1) eat real food - more vegetables, moderate meat, moderate fruits, less grains, less sugar, less vegetable oils.
2) exercise - moderate intensity cardio, sprinting, heavy lifting, dedicated stretching and mobility.
3) live - relax, de-stress, meditate.
Disclaimer: I'm not professionally qualified to make any formal recommendations. I've just done my homework and I'm my own guinea pig. All of my data, unless otherwise cited, comes from a sample size of n=1 (me).