The best advice, have the wedding you and your fiance want. Not what someone else imagines your wedding should be.
Regrets for mine, being forced nagged by PIL to have Dh's sister as a bridesmaid. I hardly knew her, I think I met her 4 times? My other bridesmaids were my best mate and my two sister who I definitely did want as my bridesmaids. As Dh and I were paying it meant we bore the extra cost of SIL's dress, flowers, shoes, tiara thing.
On pretty much every photo she looks like she is sucking a lemon. Not smiling at all even though everyone else in the photos are smiling or laughing. And then, she got married 3 years later and Dh wasn't even a fucking usher. Luckily it meant no duties for Dh and backfired on PIL who were questioned publicly by relatives on bride's side as to why Dh wasn't an usher. PIL spent a lot of money on the wedding. The divorce was finalised just 4 years later. Very sad as we loved the groom.
Best bits of our wedding, only inviting immediate family, ie parents, siblings (all bridesmaids) and our very close mates. Having 2 photographers, one for the groom getting ready, one with me. Mostly casual shots with a few lines up but because it was very small no one standing around for an hour whilst the photos were taken.
Great food, winter wedding, roast dinner and you could pre-order chicken or beef. Cheap wedding dress, handmade by Mum's friend, beautiful fabric so not cheap looking just not spending £1k on a dress you wear once. Cheap table decor as no one gives a shit. Flowers only for bride, bridesmaids, buttonholes, corsage for the Mums. None in the church, none on the tables.
Having both my Mum and my Dad walk me down the aisle because they both raised me, Dad played an active role.