I've done a couple of seasons now.

Apart from my own SPS debacle, due to my cognitive decline, I like Splinterlands very much.

Differences Between the Leagues

Each league level tends to operate in a different way.
I get very competent at battling in Silver, using certain cards with up graded powers. But, then, the new Season means recommensing from a league lower, the combos are different, and I found myself back down near NOVICE rather quickly. However, with perseverence, I regained my form to tread back upwards.

Renting to Increase League Level

This Season I had a high enough rating to reach league Gold 1. But, my card power was still only Silver 1. So, with some DEC that I've built up via playing and renting in previous seasons, I figured I could afford to RENT the power I required.

I first thought that GOLD 3 would be fine, but then figured the bonus Chests are too tempting. Also, when I start next season my Rating will be higher. While, I am planning to buy more packs, it might be worthwhile to start in a Gold League and I may have enough Card Power after opening a few packs.

Renting Earlier than Later in the Season

I chose to rent cards for the next 2 days. I've rented them slightly longer than the end of season for two reasons.
Firstly, the prices of renting a card increases towards the end of the season. This is great if you are renting, as players like me want to max out their Card Power, gain cards to win battles, and so on. So, getting them earlier today was cheaper.
Secondly, I can use those cards at the beginning of next season.
This will be a good experience to see how beneficial rental cards are to improve my line up.

Every season is bringing new insights into how to play. Every league adds extra spicyness. Trying to win daily quests can make you swear at the computer screen... Onward and upward.