you can buy ready-to-use serums but i choose to diy using the products below from amazon (i don't add preservatives and HA mixed with niacinamide has to be used within a few days. Please note that HA has to be placed in the fridge (not freezer) all the time. L-ascorbic acid serum also goes bad quickly so try to use HA with that within a week or so. I make very small batches in amber glass bottles every week):
HA - i do 1%
http://www.amazon.com/BulkSupplements-Hyaluronic-Hyaluronate-Powder-grams/dp/B00GT4DL0W/ref=sr_1_2?ie=UTF8&qid=1424874920&sr=8-2&keywords=hyaluronic+acid+powder
vitamin C - start from 5% and go up to 20%
http://www.amazon.com/BulkSupplements-Ascorbic-Vitamin-Powder-Kilogram/dp/B00AYIM9Y8/ref=sr_1_2?ie=UTF8&qid=1424875001&sr=8-2&keywords=vitamin+c+powder
vitamin B3 - i usually do 2-4%
http://www.amazon.com/BulkSupplements-Vitamin-Niacinamide-Powder-grams/dp/B00GW2LXTM/ref=sr_1_6?ie=UTF8&qid=1424875027&sr=8-6&keywords=niacinamide
AHA - i started from this one below and have been using it
http://www.amazon.com/Alpha-Hydrox-AHA-Enhanced-Lotion/dp/B000052YM7/ref=sr_1_1?ie=UTF8&qid=1424875245&sr=8-1&keywords=aha
retinol -
http://www.amazon.com/RoC-Retinol-Correxion-Wrinkle-Night/dp/B00027DMI8/ref=sr_1_6?ie=UTF8&qid=1424875407&sr=8-6&keywords=retinol
http://www.amazon.com/Retinol-Cream-Vitamin-100-ounce/dp/B008AH12C0/ref=sr_1_2?ie=UTF8&qid=1424875407&sr=8-2&keywords=retinol
there are concerns about big jar opening exposed to air and finger dipping etc. it's always recommended to use a tube with small opening. but i used it and it's effective.
eye cream - contains copper peptide
http://www.costco.com/StriVectin-SD%E2%84%A2-Eye-Concentrate-for-Wrinkles.product.11622593.html
Please note that it's better to start slowly, from low concentration/less often usage as retinol and vitamin c and AHA products can all have negative impact on your skin when your skin is not built up for that tolerance level.
also try to introduce only one new product at a time to identify how your skin responds to it. If you use a lot of new things and your skin is showing something negative you don't know which product is the culprit. Also some people think copper peptide works better while others think retinol works better. You need to try and find out which works better on your skin.
furthermore, some products offset each other's effectiveness and cannot be used together so you have to separate them into your morning and evening regimen. for example, ascorbic acid and niacinamide serum cannot be mixed together. so you can try to use one in the morning and the other in the evening. Most of the products above will make your skin sensitive to sun so make sure you have sun protection all the time during the day (you should anyway but now you HAVE to be diligent about it). Sun is the biggest enemy of skin!!
you can try google by key words and find a lot more details on internet. have fun reading :-)
our skin deteriorated over a long time and it takes time to recover and get better. so don't expect miracles happening overnight. it'll take at least 4 to 6 weeks trying to see improvements...
one more note, you can research oils such as rosehip oils, argan oils, avocado oils, and essential oils such as geranium oil, rosemary oil, ylang ylang oil, etc. They are good for skin (and hair) when used appropriately.
almost forgot, chemical peels and derma rolling.. you can find more details from internet and youtube too. remember, DON'T be too aggressive!! they can have catastrophic adverse impacts if you get too aggressive! try to be patient and take your time to go slowly! or just use the topical serums and creams if you're not sure! Good luck!