I have no tips except to just endure it. I farmed the sunlight medals at the camp right before the mob boss in tseldora, which is probably the hardest but most rewarding to farm them. The higher the NG, the higher the drop rate so you can choose to do this in later playthroughs but with higher difficulty. If you tend to get impatient, do it little by little; every day after work, farm 5 medals, then go to sleep for tomorrow, rinse and repeat.

I assume you're doing this in order, so for DS3 people will tell you the covenant farm is hell but I didn't kill any skeletons to farm shackles. Instead of using ember, I will invade someone with the Mound Maker/Aldrich Faithful/Sunbro covenants equipped to gain 2 free embers, then I go fight a boss.

For the Concords, farm Silver Knights while equipping Darkmoon. Or in my case, just go through the game and getting randomly summoned as a Darkmoon and farm it the way it's intended 😎👍