I have a little something for you.
o un PIC-co-lo pen-SIE-ro per te — stress on 'pic-', 'sie-'. 'Pensiero' has three syllables: pen-SIE-ro.
Arriving at a date with a small gift — 'un piccolo pensiero' is the Italian way to say a small token of thought.
'Ho un piccolo pensiero per te' = I have a little thought for you. 'Pensiero' in Italian means both thought and a small gift — the two are connected. A 'pensiero' is not a grand present but a sign of attention and care.
Ho portato qualcosa per te.
I've brought something for you.
More direct — you have brought a specific thing
Visto che ti piace il cioccolato...
Since you like chocolate...
Remembered a specific preference — shows you listen and pay attention
Piccola cosa — ho pensato a te quando l'ho vista.
Just a little thing — I thought of you when I saw it.
The thought of them while doing something else — most romantic version
The 'pensiero' (small gift) is a deeply Italian social and romantic gesture. Arriving at someone's home with a bottle of wine, flowers, or pastries is standard practice. A 'pensiero' brought on a date — especially something that shows you remembered their preference — signals attentiveness and care.