Similar thoughts to before, gold ETFs if you're only investing small amounts as per OP. (Can stick it in an ISA that way or a SIPP if applicable).
Gold sovereigns can be bought for those sorts of amounts too and could be fun to own, better than buying other physical gold as an individual in the UK (bullion, jewelry) as there are tax advantages, no CGT or VAT (VAT not applicable to gold bullion either to be fair).
Similarly, silver coins issued by the Royal Mint have those tax advantages vs silver bullion (which is subject to VAT) and jewlery.