Not my own recipe/guide but rather a simplified text version for myself, trying to follow Medder's Miniatures' guide (you can find it in the link). Green parts are painted with a sponge.

1. Prime the miniature black.
2. Cover the armor with Guardian Green
3. Cover roughly 80% of the armor with Emerald Forest following the light direction
4. Cover roughly 40% of the armor with Leafy Green following the light direction
5. Highlight the most "top parts" with Rainforest
6. Make about 50-50 glaze of Molten Lava and Oak Brown and glaze the areas where the Emerald Forest and Guardian Green meet and push the paint to the darkest areas
7. HELMET: Prime with Mechanicus Standard Grey or any neutral grey. Use sponge to cover it with Matt White again following the light direction
8. Gloss varnish the entire model. Apply transfers/decals after varnish is dry. After the transfers are dried and set, re-gloss the model.
9. Make brown+orange oilwash. Colors similar to the Molten Lava and Oak Brown like Burnt Umber... Cover the model all over with the oilwash and let it dry for about 90mins and clean the most prominent areas with a cuetip.
10. Carefully edge highlight the top parts with Rainforest . Additionally make scratches to the armor with the Rainforest
11. Use Banshee Brown to make the scratches more 3D.
12. Paint all non-green areas like Helmet, Crux Terminatus, weapon, tubes etc. with Matt White . Paint Ashen Stone mixed 50-50 with speedpaint medium over the white areas.
13. Highlight the white areas with mix of Matt White and Ashen Stone
14. Paint the purity seals with mix of Matt White and Murder Scene
15. Paint the lenses with Blood Red . Hit the center of the lens with white, followed by Radiation Glow . Do the same steps for the helmet.
16. Finish rest of the mini like weapon and details etc.